Overheating engine protection

Submitted: Wednesday, Oct 02, 2024 at 08:47
ThreadID: 148741 Views:1434 Replies:15 FollowUps:54
Hi folks . I'm looking for a overheating warning protection monitor for my Ranger and suggestions on what others have used , I recently cooked and destroyed my PX Ranger motor and was very surprised how quickly this happened. Only checking it days earlier at the time the engine cooked and seized . The factory gauge was still showing normal running temperature at the time.
Years ago I used to have a fitting in the engine block low down with a warning light and gauge so this may be a option . Thanks for any suggestions you may have .
Cheers nick

Red arc coolant monitor
Cheers Nick b

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Reply By: Peter_n_Margaret - Wednesday, Oct 02, 2024 at 08:57

Wednesday, Oct 02, 2024 at 08:57
I have a RedArc coolant alarm in the OKA.
EDIT: The probe is fitted to the radiator header tank.
Cheers,
Peter
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Follow Up By: Member - nickb boab - Thursday, Oct 03, 2024 at 09:12

Thursday, Oct 03, 2024 at 09:12
Thanks peter . What is in the kit please.
I can't seem to see that on line nor how the kit is configured .
Nick
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Follow Up By: Nomadic Navara - Thursday, Oct 03, 2024 at 10:10

Thursday, Oct 03, 2024 at 10:10
There is plenty of info online. Try using DuckDuckGo to find it.

RedArc coolant alarm
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Follow Up By: Member - nickb boab - Thursday, Oct 03, 2024 at 12:11

Thursday, Oct 03, 2024 at 12:11
Thanks have now found . Cheers
Cheers Nick b

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Reply By: Member - John - Wednesday, Oct 02, 2024 at 09:20

Wednesday, Oct 02, 2024 at 09:20
nickb, I have a block temp alarm as well as a low water level alarm, https://www.vpw.com.au/parts/DC-1035 and https://www.fullwavemarine.com/tempgauge.html
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Follow Up By: Member - nickb boab - Thursday, Oct 03, 2024 at 09:04

Thursday, Oct 03, 2024 at 09:04
Thanks J&J . Craig Davis was the sort of thing I was thinking of . I think the red arc sensor in the header tank would be a good option for the ranger so as soon as the water level drops in the tank you are warned .
Cheers Nick b

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Reply By: Member - Duncan2H - Wednesday, Oct 02, 2024 at 10:19

Wednesday, Oct 02, 2024 at 10:19
My gold standard is:

1. An Engine Watchdog (tm) with the thermocouple bolted to a thermostat housing bolt. I have the audible alarm set at 10deg above what a big hill climb causes.

2. A Low Coolant level alarm grafted into the top radiator hose.

Monitoring block temperature is not great, the block has such huge thermal mass that by time its heated up enough to generate an alarm the cylinder head is well and truly cooked.

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Reply By: Member - Bigfish - Wednesday, Oct 02, 2024 at 10:24

Wednesday, Oct 02, 2024 at 10:24
gET YOURSELF A SCANGAUGE OR AN uLTRAGAUGE. bEST UNITS OF THEM ALL...SO MANY THINGS THEY CAN MONITOR AND ALRMS CAN BE SET TO SUIT.
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Follow Up By: RMD - Wednesday, Oct 02, 2024 at 18:19

Wednesday, Oct 02, 2024 at 18:19
Scangauge uses the same sensors which don't indicate when water lost or head gets too hot. NOT THE SOLUTION. IT WILL NOT SAVE AN ENGINE! Most scangauge functions aren't critical engine saving features. I have one and it IS USELESS TO SAVE AN ENGINE!
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Reply By: Rangiephil - Wednesday, Oct 02, 2024 at 10:32

Wednesday, Oct 02, 2024 at 10:32
There is a very cheap LED gauge you can buy that is listed as "temperature controller." on ebay. Costing under $30
I had one on my D2 with the sensor on one of the thermostat housing bolts and it saved my engine when I had a leak occur on one of my hoses. I had to insulate it from ambient with some Blu tack LOL.
https://www.ebay.com.au/itm/387200769376?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D272500%26meid%3D7c394e35778445808d427007a3a4f794%26pid%3D101875%26rk%3D1%26rkt%3D4%26sd%3D166290787997%26itm%3D387200769376%26pmt%3D1%26noa%3D0%26pg%3D2332490%26algv%3DSimVIDwebV3WithCPCExpansionWith2ColRanker%26brand%3DUnbranded&_trksid=p2332490.c101875.m1851&itmprp=cksum%3A3872007693767c394e35778445808d427007a3a4f794%7Cenc%3AAQAJAAABMAIY39866gaArUjrJ%252B%252F5tyl1XplgQtYouv7uMlkdVwXQZowxSQSLtPSuwVlG33jyEO37maQCqcYAtj9fp%252FVdq5GNLyNb9TmFDQjloy17tfvyoD%252BqYiZ4P2GEbYsEJljCGi%252FBJydiNJlJE9Cyfl9PkV47ykOgt2e%252FaGoTWClT5yEN1FKxE42sa39MFntveiiLwbhkBVLn47aEH4%252BkqlnwKs6iZYoe%252Fbvgeomt9spwxEt6hj3ZphDQM5wX4toonKK1H7qE2U52JsUD0vYB0L6Nn6tXKvhzTGdpDU3zjDgbNxlueK5xoQaekx8ANDR6Al2mLRMqFfYAwW3Kws%252FTInrc2RZfJmFsbbVscgw%252BM0A%252Fv4qi7YeE%252FtpA4YOmoOrLUmcQpSLWFVCv6y9KvA7lAKSneFI%253D%7Campid%3APL_CLK%7Cclp%3A2332490&itmmeta=01J95A4THFK000VBKE25RC9069
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Follow Up By: RMD - Wednesday, Oct 02, 2024 at 18:23

Wednesday, Oct 02, 2024 at 18:23
I use an eBay programmable digital display and fitted a 8mm screw in sensor to the cyl head. Simple to calibrate! It is the head which get too hot too quickly. Fitted an alarm to it's small relay and it tracks the cyl head temp very well set to temp you want the alarm to sound. $20
Edit.
The combustion in the engine cylinder hits the piston crown and the cylinder head. As the piston descends the cylinder walls, heat is given to the cylinder walls progressively less as the piston descends. You cannot fit a temp sensor to the piston so the Cylinder head is the ideal place BECAUSE IT IS the section which gets hottest quickest, when there is NO WATER. The cylinder head is ALWAYS GETTING HEATED. A sensor down in the block means the head is already TOAST before the block gets too hot.
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Reply By: Member - LeighW - Wednesday, Oct 02, 2024 at 12:10

Wednesday, Oct 02, 2024 at 12:10
Two aspects to this, slow overheat caused by high engine loads and poor cooling and fast overheat caused by a sudden lose of coolant.

Devices such as the scan gauge can pick up slow overheats but will most likely miss a fast overheat as the sensor relies on water temperature to operate it and if you have a sudden lose of coolant there is no water to operate the sensor.

To protect against fast overheat you realy need a lose of coolant alarm.

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Reply By: RMD - Wednesday, Oct 02, 2024 at 19:30

Wednesday, Oct 02, 2024 at 19:30
Nick B
Down low, on or in, the engine block is the worst place to have a sensor. Too late Mate.
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Follow Up By: Member - nickb boab - Thursday, Oct 03, 2024 at 08:49

Thursday, Oct 03, 2024 at 08:49
RMD . Wouldn't that be the only place that there was water left in motor ??
my thought was that in the event of a mass leak the water will be pumped out of the radiator and head first ?
Nick
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Follow Up By: RMD - Thursday, Oct 03, 2024 at 20:00

Thursday, Oct 03, 2024 at 20:00
Nick.
I agree there may be water still in the lowest part of the block, but that means the cylinder head is TOTALLY uncooled and rising in temp. Even if a small hose or an upper rad or lower rad hose blows and loses water fast, the cylinder head temp will rise quickly. Way faster than the lower block area. Therefore, if the NTC probe is in a, screwed into head sensor, it will also rise in temp as it too is heated. At a set temp it will then sound the alarm and immediate action taken to prevent further overheating past a dangerous level. The leak through an EGR Cooler is also then covered in the heat temp rise. Some.people.fit a pressure gauge into the cooling system and It can be seen to drop when loss of pressurization happens.
As Allan said, a water level sensor can also be fitted to detect less than optimal and it will.suddenly alarm if either drop out or sudden dump.of coolant happens. They work well too.
Many ways to skin the Feral cat!
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Reply By: Stanley S - Wednesday, Oct 02, 2024 at 21:58

Wednesday, Oct 02, 2024 at 21:58
Don't use engine more
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Reply By: Batt's - Thursday, Oct 03, 2024 at 08:52

Thursday, Oct 03, 2024 at 08:52
Temp gauge in the dash hasn't let me down yet in the dozen vehicle's I've owned since 1985.
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Follow Up By: Member - nickb boab - Thursday, Oct 03, 2024 at 09:19

Thursday, Oct 03, 2024 at 09:19
1985 that old school .. lol :))
Nothing like the cars hey
Cheers Batts
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Follow Up By: Allan B (Sunshine Coast) - Thursday, Oct 03, 2024 at 11:34

Thursday, Oct 03, 2024 at 11:34
.
Batt's, the only reason you have not been "let down" is because you have not experienced a catastrophic coolant loss yet. The dash temp gauge won't help ypu then. Ask me how I know.
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Follow Up By: Batt's - Friday, Oct 04, 2024 at 08:50

Friday, Oct 04, 2024 at 08:50
I beg to differ had a 1975 fj40 that had radiator hose come loose and started leaking the temp gauge went up pretty fast lucky I noticed. It's a bit different comparing old vehicles to new you can have more trust the old vehicle's gauge with rise in temp modern can go the opposite way which will confuse the operator.
I have had a hired work vehicle fail 20 or so yrs ago about 100k's out of Mackay it was a falcon . The temp gauge started to drop the auto box started playing up which was odd neither myself or co worker new what was going on we pulled over but it was too late. Popped the bonnet it was bone dry, cooked the racq came out about 30 minutes later he said it was stuffed, said stand back and watch this he poured water in the radiator and it erupted like a volcano. It got a new 2nd hand motor installed via the companies insurance.
Like usual modern tech is supposed to be good but it creates it's own issues sometimes. These days we often can't rely on what our dash readout says so we need a 2nd gauge to back it up to me that's a big step it the wrong direction but some people think it's wonderful like oh man look at this cool gauge I had to buy because the factory one can't be trusted. It's just like all the other crap they add to vehicles that is ready to fail go the future of the motor industry.
That's why I'm reluctant to buy a new vehicle these days we have had 2 in the past both with never ending issues across a wide rage of item failures.
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Reply By: Member - nickb boab - Thursday, Oct 03, 2024 at 09:49

Thursday, Oct 03, 2024 at 09:49
Slightly off topic..
In regards to the ranger engine and maybe a warning to others .
I can't say I wasn't warned of this problem I had seen this and heard of it many times before .
My thoughts was I would see warning signs before I.e the water level dropping or maybe temperature Rising before any damage my occur .
But was shocked to see how quickly it happened within 20 minutes of leaving
my house in the morning it was cooked
Interesting that Ford told me that it's not only the EGR problem but the head as well and can go within weeks of each other . I haven't got the final bill yet but just to fit a second hand engine it will cost me a minimum of 12 K imagine that if you were out bush and that happened

Cheers nick
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Reply By: Member - Duncan2H - Thursday, Oct 03, 2024 at 09:58

Thursday, Oct 03, 2024 at 09:58
I dont even trust factory temperature gauges in vehicles.. Toyota were fitting a zener diode circuit to their gauges in the 90s to lock the gauge in at a set point and hide the normal fluctuations. By the time the temperature had risen enough to cause the gauge to start moving again the head was often cooked, quite a disgusting design.
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Reply By: Allan B (Sunshine Coast) - Thursday, Oct 03, 2024 at 12:06

Thursday, Oct 03, 2024 at 12:06
.
Nick, Temperature gauges, no matter where the sensor is located, will not warn you when a catastrophic coolant loss occurs, such as a failed radiator hose, or a heater hose for that matter. Believe me, I know!
Even with a slow coolant leak and some resultant engine overheat, the OEM temperature gauge may indicate this but will you notice it without an audible alarm?

The most likely event to cause sudden overheat is loss of coolant level which first reveals itself in the radiator head tank. A coolant level alarm with audible buzzer is the only reliable way to monitor this. You will receive the warning even before the engine temperature begins to rise.

Redarc make such a device and as is usual with Redarc, it is of good quality. However it has no internal audible alarm so you need to supply and fit one of your own. It is also does not come with the required sensor electrode and is overpriced.
Davies Craig offer an essentially identical model but with an internal buzzer, comprehensive sensor and fitting kits, and at a lower price. That would be my recommendation.
I designed and built my own system but it does need some skills to do so.

I observe that people seem to focus on radiator hoses as being the risk component but the small heater hoses are just as vulnerable but invariably overlooked in maintenance.
Also, carrying spare hoses seems to be the norm, but they are only of value after the event of hose failure occurs. My practice is to replace all hoses, radiator and heater, each season. Not much trouble or cost and it avoided the crisis arising in the first place. Even then, I did experience a leak in a new bottom hose that only occurred when the system was at pressure. My alarm warned me before any disaster.
Cheers
Allan

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Follow Up By: axle - Thursday, Oct 03, 2024 at 13:06

Thursday, Oct 03, 2024 at 13:06
G/day Allan,
I reckon my nose is just as sensitive as any electrical device, that escaping coolant smell , pick it a km away!
The main thing is STOP! no matter where you are.



Cheers Axle.

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Follow Up By: Member - nickb boab - Thursday, Oct 03, 2024 at 18:58

Thursday, Oct 03, 2024 at 18:58
Thanks Allan for the heads up on the redarc probe NOT being inc the price $275 .
Davis Craig low coolant alarm is that this one Davis Craig low coolant
I know you can buy these cheaper .

Axle sure you can smell coolant from a leak in the engine bay but not so in the case of a ranger pumping fluid out the exhaust via EGR housing at a very fast rate . In my case even when I opened the bonnet there wasn't a strong smell of hot coolant.
Cheers nick
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Follow Up By: Allan B (Sunshine Coast) - Thursday, Oct 03, 2024 at 19:54

Thursday, Oct 03, 2024 at 19:54
.
Yes Nick, that's the one, Davies Craig, but they can be found on eBay cheaper like this one.
Cheers
Allan

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Reply By: Member - Cuppa - Thursday, Oct 03, 2024 at 13:20

Thursday, Oct 03, 2024 at 13:20
After coolant loss/overheating, not picked up by the temperature gauge in our bus, when we bought our Patrol I fitted one of these at what was just about the highest point of the coolant system. It's brief self test beep & red light flash each time I turned on the ignition was very reassuring over the next 10 to 12 years.

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Follow Up By: Allan B (Sunshine Coast) - Thursday, Oct 03, 2024 at 18:06

Thursday, Oct 03, 2024 at 18:06
.
Great move Cuppa, however:
The EngineSaver "self test" feature of "beep and flash" at power-up is actually just a reaction that signals 'power available'. It may be some reassurance but does not actually test the device function. Many products make the same "self-test"claim.
A way to determine that a Low Water alarm works correctly is to periodically disconnect the sensor which thus produces a simulated low water condition and should activate an alarm condition. But this is not a complete system test as it is possible to have a false high-water state due to fouling of the electrode from iron oxide deposition on the sensor. The only way to fully test the system is to actually lower the water level by partly draining the radiator to below the alarm level which will test both the sensor and receiver.
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Follow Up By: Member - Cuppa - Thursday, Oct 03, 2024 at 18:28

Thursday, Oct 03, 2024 at 18:28
Allan, I expect you'll be pleased to know that in the time I owned the Patrol after fitting the engine saver I never once had a low coolant situation to trigger the the alarm, but that I did, once in a while, disconnect the sensor to test it. When preparing the vehicle for sale I removed the sensor (it was a screw in type, which screwed into the air bleed hole in the thermostat housing above the water pump) to have a look & found it 'clean as a whistle', probably due to my only ever having used a rainwater /coolant mix in the system.
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Follow Up By: Member - nickb boab - Thursday, Oct 03, 2024 at 19:21

Thursday, Oct 03, 2024 at 19:21
Allan my original thought was to put a redarc probe into the radiator header tank but I'm not sure that is a constant coolant supply to the radiator or more like only supply as needed . Waiting to get the vehicle back to check on that ..
But that would make it alot easier to check it was working correctly.
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Follow Up By: Allan B (Sunshine Coast) - Thursday, Oct 03, 2024 at 20:00

Thursday, Oct 03, 2024 at 20:00
.
Nick, By "header tank" I meant the top chamber of the radiator itself.
Maybe you thought I meant the expansion/reservoir tank connected to the radiator overflow by a small tube? No, certainly not there.

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Follow Up By: Allan B (Sunshine Coast) - Thursday, Oct 03, 2024 at 20:14

Thursday, Oct 03, 2024 at 20:14
.
Yes Cuppa, the problem of sensor fouling with iron oxide and other muck is generally when a system has only water, and doubtful quality at that. Commonly yesteryear.
Your use of quality water and coolant mix was likely to suppress contaminants satisfactorily.
But my warning still stands for some.

I don't like the type that screw into the air bleed hole near the water pump. I prefer to fit the sensor into the radiator header tank in order to sense the falling level at the earliest opportunity.
There are innovative ways to fit an electrode there provided that the tank is plastic, not metal.
Otherwise an external sensor in the top hose can be used.
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Follow Up By: RMD - Thursday, Oct 03, 2024 at 22:04

Thursday, Oct 03, 2024 at 22:04
Nick.
I too think you may have meant the overflow tank reservoir. When the vehicle is operating, that tank IS NOT part of the cooling system and ONLY allows for the HEATED VOLUME CHANGE to be held , ie OVERFLOW and returned to the HEADER TANK TOP, of the radiator as it cools. The RADIATOR CAP CONTROLS THAT ACTION.

Just a note from before re, hoses. Yes, an EGR can somehow split, ie low QUALITY production, bit many vehicles have VERY POOR QUALITY radiator hoses and don't last long at all. Often service mechanics DO NOT thoroughly inspect hoses or fan/drive belts either. A crucial thing if reliability is paramount.
Mostly mechanics DO NOT remove and inspect the INSIDE of hoses where the BLOWOUT sudden failure cracks/faults are visible, the outside MAY LOOK OK At that time but inside NO!
Key is Quality hoses and Quality mechanics!
Some manufacturers DO use FAR BETTER hoses than others. and drive belts too.
I had a HJ61 turbo LC for 25 years and sold it with every hose STILL ORIGINAL. Never replaced ANY HOSE in 25 years. I did want warranty of the steering pump belt as 72,000km however. It only lasted that distance. Other belts OK.
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Follow Up By: Member - nickb boab - Friday, Oct 04, 2024 at 08:49

Friday, Oct 04, 2024 at 08:49
The Rangers radiator cap is on the Reservoir /header tank . The lower outlet is a lot larger than the normal size and it maybe a continuous supply of coolant to the radiator . "Not expansion"
The top tube is a return line from engine or radiator I.e expansion . This I am sure .



My theory was that the tank is a header tank and Reservoir , if this was the case (yet to be confirmed) then if the sensor was in the Reservoir tank any loss of water / coolant would be realised before any loss out of the rest of the cooling system .
Nick

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Follow Up By: Allan B (Sunshine Coast) - Friday, Oct 04, 2024 at 09:26

Friday, Oct 04, 2024 at 09:26
.
That is an unusual setup Nick. I have never seen anything like it. But as you say, it appears like a head tank.
Where do the upper and lower tank connections go to on the engine? Is this tank mounted high in the engine bay?
As you say, it may be an appropriate place to sense the system coolant level.

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Follow Up By: Member - nickb boab - Friday, Oct 04, 2024 at 11:07

Friday, Oct 04, 2024 at 11:07
Allan . As you can see the tank is high up at the back of the engine bay . I don't know where the pipes actually attach to the engine as I don't have the vehicle with me at present , it is still in sickbay .
I know the top pipe is return line because when I did get the vehicle started after its catastrophic meltdown the water/coolant was spewing out the top pipe back into the Reservoir tank . I think it was Ford that told me when it reaches pressure and blows off it comes out under the tank & under wheel arch



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Follow Up By: Allan B (Sunshine Coast) - Friday, Oct 04, 2024 at 15:56

Friday, Oct 04, 2024 at 15:56
.
From what I can see online, that tank is a regular expansion/reservoir tank. So any level alarm would be more effective if positioned near the top of the radiator inlet header, the radiator being a cross-flow.
Someone else with a Ranger may have more positive information.
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Allan

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Follow Up By: Member - Happy Explorer - Sunday, Oct 06, 2024 at 16:37

Sunday, Oct 06, 2024 at 16:37
Hi Nick
Old Volvos had a similar setup. The radiator cap was actually on that 'overflow' tank. I didn't like it as it meant the full radiator pressure was also in that tank and when they aged they tended to look rather crazed. They also had plastic/aluminium radiators long before I saw them on anything else.
Off topic I know.
Roy G.
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Follow Up By: Member - Cuppa - Sunday, Oct 06, 2024 at 16:41

Sunday, Oct 06, 2024 at 16:41
Our 4.2 GU Patrol was the same Roy.
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Reply By: Member - PhilD_NT - Friday, Oct 04, 2024 at 19:07

Friday, Oct 04, 2024 at 19:07
I've read all the replies so far and it seems to me that everyone seems stuck on the similar path of water loss monitoring, but I'd like to suggest an alternative that was successful back in the 1970's for me.

The car I had then had issues with the electrical gauges and their reliance on a troublesome power feed. I decided to rip it all out and replace with a full set of Smiths gauges with some critical ones being mechanical for temperature and oil pressure etc. In doing the dash panel I ended up with a final space to fill. In looking through the Smiths catalogue I spied a possible answer to this issue of hose failure. It occurred to me that temperature monitoring was not the best due to the sensor when exposed by water loss would just read the air temp in the system. A water level sensor would mean that I had already lost a significant amount of water.

But this gauge was a mechanical pressure one. It took me a bit of trial and error to find a proper access point to monitor as a couple were in the pump suction side. It was working well, and I finished it up in time for a long interstate trip from Darwin to the east coast, down to Sydney and headed across to Adelaide. Halfway between Hay and Balranald the gauge proved its worth. I was lucky to be glancing at the gauge just as it suddenly went from its normal steady reading to near zero. A quick stop, lift bonnet and see a heater hose streaming water. Took me about 10 minutes to patch or bypass hose (can't remember which), replace minimal water loss and be on my way again.

The downsides to this particular gauge though is that a few months later the very small copper tube feeding it got blocked', and that it needed to have an audible alarm as well as visual.

Surely though there may now be some other type of pressure sensor that could achieve a similar but more reliable outcome. If there is, I'd buy it.
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Follow Up By: Allan B (Sunshine Coast) - Friday, Oct 04, 2024 at 21:25

Friday, Oct 04, 2024 at 21:25
Hi Phil.

In considering supervision of the coolant system by pressure measurement I offer the following:

The pressure in the system is largely created by the temperature rise of the coolant in a confined containment which attains an equilibrium. If a major leak occurs, as in your case, then there may be sufficient system pressure drop due to volume loss. But if the leak is slower the pressure will be maintained as vapour is generated above the coolant to restore the equilibrium. So the pressure switch will not be activated until enough coolant is lost to destroy the system equilibrium. By this time you will have lost a lot of coolant and the engine temperature will have risen considerably. Accordingly, I do not consider supervision by this means to be reliable.

As the criteria is to detect coolant loss, measurement of coolant level is most appropriate. It is direct measurement which is always preferred over inferential measurement such as pressure change. Furthermore, it is functional as soon as the ignition is turned on, even before engine start and does not require generation of coolant temperature and pressure buildup.
Detection of level fall is simple to achieve using an electrode and delivers directly in digital form to activate an alarm.
Cheers
Allan

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Follow Up By: Member - PhilD_NT - Saturday, Oct 05, 2024 at 00:34

Saturday, Oct 05, 2024 at 00:34
Allan, Like the OP I also have a PX Ranger and a common failure these have is the EGR cooler. When it fails it is not always total and immediate, but under those circumstances it may well work and give the owner a chance to turn off the engine before the failure causes further engine damage.

In our case the failure was quite slow. We were 3000km from home with only one Ford Dealer about halfway. I noticed the level slightly lower than normal in the remote mounted expansion/overflow tank than so just topped it up. we continued home and at every stop, fuel, rest or nightly, I rechecked and topped up. It amounted to about 2.5 liters for that distance. There was no visible external leak or the suggested white smoke out of the exhaust for an EGR failure condition.

At home I booked the vehicle in as it was still under warranty, and it had to be tested overnight to detect a pressure drop. Cooler replaced.

I have no idea with the kits that measure low coolant loss as to how much has to be lost before they activate an alarm condition, but as to my slow leak you would have to negligent in not doing a check under the bonnet at least daily for all fluid levels and it shouldn't get to the stage of the level alarm activating. Is there one of these kits that actually checks the level in such a remote tank, not in a radiator hose? I had looked up a couple a few years back but didn't see one then.

I'm now a bit paranoid and check the coolant level more than once a day on a trip until I can hopefully get the EGR cooler permanently blocked and bypassed.

Personally, now that I've had both a rapid and a slow leak condition, I would prefer to have a system that can cover both incidences.
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Follow Up By: RMD - Saturday, Oct 05, 2024 at 07:45

Saturday, Oct 05, 2024 at 07:45
Phil D and Nick
If the coolant level is becoming too low, there is not enough cooling action happening, Especially if THAT coolant is also being used to cool the Auto fluid as well. The level in a tank is one way and works well via sensor of some type. There will always be a sensor and nothing is perfect.
The cylinder head IS the item which will get the hottest the quickest if coolant is low or GONE. My preference is to have the SENSOR screwed into a threaded hole, usually some spares so it can monitor the temp ALL the TIME. If it exceeds a set threshold and alarm sounds. Normal daily checks should pick up any anomalies of coolant loss and register with an aware owner, ie, preventative maintenance! Because the IN HEAD sensor runs all the time you can see the digital reading and know when load is high and also if coolant is disappearing, Yes the level ones do that too, but don't indicate any running temp variations up to the critical degree.
Because they are all wiring electrical systems used, similar failures of any detection system can occur. The DIGITAL reading with NTC sensor screwed into the head does the JOB ALL THE TIME and warns of over heat if coolant loss or high auto temp has exceeded the ability of the cooling system to cope with it all.
PS don't use a NTC sensor in a tag under a bolt head, if you can help it. They are in engine heat breeze and can't sense as well or as quickly.

My Ebay adjustable/settable circuit and an alarm fitted to the relay on the board tracks my Scangauge temp reading OE vehicle sensor within 2 degrees. If water disappears the Scangauge with not read properly but the IN HEAD sensor WILL and indicate and ALARM too. Scangauge and IN Dash gauge WILL NOT.
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Follow Up By: Member - nickb boab - Saturday, Oct 05, 2024 at 09:52

Saturday, Oct 05, 2024 at 09:52
Thank you fella's . Not discounting any of the previous suggestions . someone else has suggested the engine guard , having a look at that I thought that might have some good options . it has 1 , 2 or 3 senses options and thought you could put one sensor on the head like suggested as well as maybe one to pickup up oil temp on the sump or similar location .
Engine guard

There is a few youtube videos on this .
Cheers Nick b

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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 11:31

Saturday, Oct 05, 2024 at 11:31
.
Hi Phil,

You ask "Is there one of these kits that actually checks the level in such a remote tank, not in a radiator hose? "
Answer: The available kits offer varying arrangements for installation of the sensing electrode.:
a) In the radiator head tank by installing a provided boss to accomodate the electrode.
b) In the air bleed hole near the coolant pump or thermostat housing using a provided adaptor.
c) By providing a sleeve for insertion into the upper radiator hose to accommodates the electrode.
d) By providing no electrode at all and leaving it to the user to determine a method.

These various methods result in varying validity in determining coolant loss. The location that affords the earliest indication is achieved by monitoring the upper level of the coolant which is of course in the radiator head tank. Thus the method which best achieves this is a) The electrode in the radiator head tank or an equivalent location such as in the upper hose. In my case, I was able to fit an electrode in the spigot from the tank that accepted the hose. Any lower location such as the air vent down on the motor will result in a delayed alarm response which may or may not be acceptable for a reaction to the event. Not adequate in my consideration. You don't want the sign that the bridge is fallen on the edge of the abyss, do you?

Installation of the electrode in the expansion/reservoir tank is utterly useless. This tank provides coolant to the system only when the engine is at rest and cooling. As it cools the contraction reduces the system pressure to the point where it eventually "sucks" fluid from the expansion tank into the radiator. Whilst the engine is running and hot, any loss of coolant due to leakage does NOT cause fluid to pass from the expansion tank to the radiator. Hence, as there is no fall of the tank level it cannot annunciate the loss until the engine fully cools.

In my book, the only location to detect a fall of coolant is in the radiator head tank or upper hose.
Bear in mind that I have spent my working life in process control where measurement and alarm of fluid behaviour were an essential part. I believe that I have picked up a clue or two about it.




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Allan

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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 12:21

Saturday, Oct 05, 2024 at 12:21
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Yes RMD, I agree with what you say above.

It is salient that what we are concerned with is over temperature of engine components. In particular the pistons and head & block.

It would be extremely difficult, if not impossible, to measure the piston temperature and even measuring the block effectively presents challenges. Location of the sensor is critical. Embedded in the block close to the cylinder would be best possible, with under a bolt head on the cylinder head as a reasonable second choice provided that it is shielded from the cooling effects of air passage, as you noted.

An engine may experience over-temperature from a number of reasons but a likely one is coolant loss which is reasonably easy to supervise as per my followup to Phil above. This provide warning of impending overheat before it even begins. So my recommendation is to install both coolant level and engine over-temperature warnings which need to be audible alarms to be effective. The event can develop rapidly and a periodic glance at dashboard indication gauges and lamps is not adequate. It must be audible to alert without delay. The OEM temperature gauge is only of benefit to warn of slowly progressing over-temperature and ScanGauge indications are not adequate for alarm function.

I am surprised that none of the alarm devices currently available offer a product incorporating monitoring of both level and temperature. It is so easy to construct a product with both outputting a common alarm.
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Follow Up By: Peter_n_Margaret - Saturday, Oct 05, 2024 at 14:02

Saturday, Oct 05, 2024 at 14:02
If coolant is pressurised, it can get to temperatures well above 100C without boiling.
This will be the normal monitoring condition.

If pressurisation is lost, it will boil at a lower temperature.
How does your temperature monitor detect that?
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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 15:33

Saturday, Oct 05, 2024 at 15:33
.
Who are you asking Peter?
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Follow Up By: Peter_n_Margaret - Saturday, Oct 05, 2024 at 16:02

Saturday, Oct 05, 2024 at 16:02
Anyone who cares to answer.
I don't believe that temperature monitoring is a reliable option until the coolant is gone and then it is too late......
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Peter
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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 16:09

Saturday, Oct 05, 2024 at 16:09
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Peter, I guess that it is I that you question, so I will attempt to satisfy your apparent curiosity.
Or is this a classic Dorothy Dixer? Either way, here we go…….

I do understand the phenomenon of boiling point elevation with pressure increase, so won't go there.
And yes, "If pressurisation is lost…." whilst the coolant temperature is above 100C then it will boil, often quite rapidly, until the system reaches equilibrium at 100C or less. If there is any coolant left at that point of course.

So now we are at your question of "How does your temperature monitor detect that?"
Well, it detects that in the same way that it detects temperatures above 100C and if it has a readout, it displays the instantaneous temperature, be it above, at, or below 100C.
But somehow I think that is not what you are wanting me to say.
I think you may be implying that if the instrument is an alarm with a set point above the 'normal' operating temperature of the motor, then a coolant system temperature falling below that set point will cause the alarm to cease sounding. If so, then you have received the warning and hopefully will pay due attention to it. Of course, an instrument could easily be configured to latch at the alarm event until accepted by pressing a button to silence, but I cannot see a need for that in this application.

Now Peter, if I have not satisfied your question, please let me know.
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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 16:27

Saturday, Oct 05, 2024 at 16:27
.
Ah Peter, you say "I don't believe that temperature monitoring is a reliable option…."
if you had said that in the first place it would have saved me a lot of time.

I see what you are getting at. If you are monitoring engine temperature and suffer a coolant loss you will receive no warning from a temperature alarm until the coolant has disappeared and the engine has increased in temperature above the set point. In which case the engine may well reach a temperature where harm may occur. Yes, it is too late!

I agree with you wholeheartedly. it is a very poor way of monitoring for coolant loss, and I have expressed that earlier in this discussion. Engine temperature monitoring is useful to detect a problem arising from engine overload or water pump belt break etc.. But. if you wish to guard against coolant loss issues then it is best to measure the coolant level.
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Follow Up By: Peter_n_Margaret - Saturday, Oct 05, 2024 at 16:34

Saturday, Oct 05, 2024 at 16:34
I suggest that an audible alarm will not (should not) alarm at elevated "normal" temperatures and therefore won't alarm when the temperature drops due to initial loss of coolant.
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Peter
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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 16:56

Saturday, Oct 05, 2024 at 16:56
.
Now I am seeing where you are coming from Peter.

If a vehicle is operating "normally" the edge block temperature and the coolant will be at about 118C.
If there is now a coolant loss sufficient to fail removal of the engines generated heat then the engine temperature will begin to rise and reach the alarm set point thus sounding an alarm.
As the temperature is being monitored at the engine, the partial or total loss of coolant has no direct bearing on this function. The engine temperature rises…. the sensor on the engine detects this and the alarm sounds. BUT TOO LATE to act in preventing engine damage in all likelihood. This is of course what I have been saying all along. We do agree, do we not? It is those other dummies who believe temperature sensing protects from coolant loss. Disclaimer… I use the term "dummies" in the nicest possible way without malice or inference of an intelligence shortfall etc. etc..


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Follow Up By: Member - nickb boab - Saturday, Oct 05, 2024 at 16:59

Saturday, Oct 05, 2024 at 16:59
Hi Allan. Going back to what we were talking about earlier with the px Ford Ranger cooling system . Is it a expansion or header tank ?? I have been assured by a higher authority that it is a header tank. "closed loop circuit" engine radiator header tank and hoses . Fluid flows from the tank to the engine / radiator

And who is the higher authority FB
HAHA : )))
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Follow Up By: RMD - Saturday, Oct 05, 2024 at 17:47

Saturday, Oct 05, 2024 at 17:47
I understand coolant can be above boiling point and if coolant is lost then it BOILS OFF quickly. However, if my engine coolant was above 100C then the cooling system isn't doing it's job very well and having a Head temp sensor detect some degree above NORMAL works well. Coolant loss or no loss. I don't want to have my engine running way up high and close to the borderline at Peter's 118C. SO, the alarm is set lower so you don't get to the critical catastrophic no return point. Simply not wise to do that!

Just my opinion about Fords. They seem to do things, re, coolant systems, in mysterious ways. The way the Rangers are, rely on a multitude of hoses and connections, all introducing more failure points. in which case the Integrity of more items has to be BETTER, or reliability is LESS. EGR's not included here. I don't like a big plastic container at the 21psi cap pressure shown above.
A few years back, Ford Mondeo had a MAZE of coolant pipes and Formed rubber T connections, midline of hoses etc. For about 2 years you could NOT BUY a second hand Mondeo engine in AUSTRALIA. So many engines were totalled by the FORD design. There Were NO SPARES anywhere. Rubber hose quality was poor.
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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 18:20

Saturday, Oct 05, 2024 at 18:20
Hi Nick,
Perhaps I should not be using the term "head tank" in respect to auto radiators.
It is sometimes used regarding steam boilers and I borrowed it from there.
Research suggests that the chamber at either end (or side) of an auto radiator is called "inlet tank" and "outlet tank". What I have been calling the "header" is the inlet (upper) tank.

The plastic container positioned remote from the radiator is variously named an expansion, reservoir or overflow tank. And I guess that it could also be termed as a "header" tank by some.

This came from an authoritative hydraulics source……. "A header tank is a reservoir containing fluid that is installed at a higher level than a main tank. A header tank is used to maintain gravity feed to the main tank."…….. and I think that to be an appropriate name.

So, take your pick from that lot. I will avoid "header" altogether! lol





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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 18:30

Saturday, Oct 05, 2024 at 18:30
RMD,
Water at 21psi has a boiling point of 110C
My 118 C was a guess.
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Follow Up By: Peter_n_Margaret - Saturday, Oct 05, 2024 at 20:16

Saturday, Oct 05, 2024 at 20:16
It is not "water".
Cheers,
Peter
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Follow Up By: Member - Cuppa - Saturday, Oct 05, 2024 at 20:20

Saturday, Oct 05, 2024 at 20:20
I think there is broad agreement that monitoring coolant level from the highest possible point of the coolant system is the best method because it provides the earliest warning. Pretty simple really.
See 'My Profile' (below) for link to our Aussie travel blog, now in it's 6th year.

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Follow Up By: Allan B (Sunshine Coast) - Saturday, Oct 05, 2024 at 22:13

Saturday, Oct 05, 2024 at 22:13
.
Peter,
I didn't say the coolant was water. Because I did not know the characteristics of coolant, I said "Water at 21psi has a boiling point of 110C" as a basis for my guess of coolant being 118C.
Can you advise the characteristics of typical coolant?…. Not that it really matters in this context.
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Follow Up By: Nomadic Navara - Sunday, Oct 06, 2024 at 08:41

Sunday, Oct 06, 2024 at 08:41
Way back in the days before we had cars with radiators where the top tank of the radiator was definitely higher than the motor's head, the header was the top tank of the radiator. These days, particularly with cross-flow radiators and low mounted radiators, I suppose all bets are off as to what is the header tank. Back then, the tank that took the overflow from the header tank was the overflow tank (no matter how high it was.) I think the younger members should stick to those terms or you will confuse us old farts.
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Follow Up By: Allan B (Sunshine Coast) - Sunday, Oct 06, 2024 at 09:19

Sunday, Oct 06, 2024 at 09:19
.
Right on Pete. But it's a New World that us old farts are living in. It can be easier to just sit back and say "Yeah, OK, sure, whatever" and wallow in our confusion. After all…. what do we know?
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Follow Up By: Nomadic Navara - Sunday, Oct 06, 2024 at 09:27

Sunday, Oct 06, 2024 at 09:27
Alan, on the other hand, if we don't educate the dribblies and redirect them, then our nomenclature will get all over the place and no one will know what others are attempting to describe.
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Follow Up By: Allan B (Sunshine Coast) - Sunday, Oct 06, 2024 at 09:38

Sunday, Oct 06, 2024 at 09:38
.
It's already too late Pete.
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Follow Up By: RMD - Sunday, Oct 06, 2024 at 09:50

Sunday, Oct 06, 2024 at 09:50
Allan B
Off topic a bit , but terms wrongly used is a big confusion.
With the Ranger there appears to be NO header tank as such, simply a full sealed large capacity to take up the expansion and it all stays sealed, HOPEFULLY! Highly pressure stressed though on all components with the system pressure so high. Probably for water pump cavitation prevention."
Terms used, and Nick is right in this, he is having a ChangeOver engine fitted. Now the "Septic" term is used by the indoctrinated, and they say, SWAP IT OUT. I haven't heard of anyone yet SWAPPING IT IN. Changeover used to work well. We used to buy "changeover" engines. Long or short.
People now call suspension components by other names, and also shafts ie,a tailshaft is in the rear, a front shaft is drive shaft taking drive, but it isn't a tailshaft.
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Follow Up By: Allan B (Sunshine Coast) - Sunday, Oct 06, 2024 at 10:55

Sunday, Oct 06, 2024 at 10:55
.
Yes RMD, when I look at it more closely and do some searching it becomes clearer.
Nick's Ranger appears to have a cross-flow radiator, possibly for reasons of lower height, larger area etc..
As such it does not have the benefit of a large radiator top tank to serve as a reservoir and so it requires a seperate tank to provide that function. That tank differs from the traditional expansion/overflow tank in that it operates at system pressure so the cap needs to be capable of that pressure and also performs the system pressure relief function. Nick's photos reveal that. So now the reserve coolant is contained within the pressurised system. Nick was talking sense but I did not earlier perceive it. Sorry Nick.
Accordingly, it could be appropriate to position a coolant low level alarm on that tank but it would present a challenge in safely arranging that. A simple electrode sensor would need to penetrate the tank with the risk of compromising its strength. Positioning a sensor in a radiator coolant hose may place it too low in the coolant height. It is a new ball game.



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Follow Up By: Member - nickb boab - Sunday, Oct 06, 2024 at 11:27

Sunday, Oct 06, 2024 at 11:27
Cheers Allen also to note that a sensor in the plastic tank would also require another hole for a point of contact to complete the circuit
Cheers Nick b

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Follow Up By: Allan B (Sunshine Coast) - Sunday, Oct 06, 2024 at 11:41

Sunday, Oct 06, 2024 at 11:41
.
Yes Nick, any conductivity type level system requires two electrodes. This can be achieved by a single boss type connection containing two electrodes in a single penetration or two penetrations for two electrodes. And I must say that what I might do to my own vehicle is not necessarily what I might recommend someone else does.

Vehicle manufacturers these days usually use sonic sensing modules which require no vessel penetration. They have a number of advantages but need to be incorporated into the design of the vehicle. Retrofitting would present challenges.
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Reply By: Member - nickb boab - Sunday, Oct 06, 2024 at 11:05

Sunday, Oct 06, 2024 at 11:05
Bolec low fluid alarm & or inc a catastrophic loss of fluid
Bolec low FLUID alarm

Engine guard. temperature warning alarm with upto 3 sensors
Engine guard
Cheers Nick b

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