Overheating engine protection

Thanks peter . What is in the kit please.
I can't seem to see that on line nor how the kit is configured .
Nick

There is plenty of info online. Try using DuckDuckGo to find it.

RedArc coolant alarm

Thanks have now found . Cheers

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 .

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!

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.

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

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!

1985 that old school .. lol :))
Nothing like the cars hey
Cheers Batts

.
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.

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.

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.

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

.
Yes Nick, that's the one, Davies Craig, but they can be found on eBay cheaper like this one.

.
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.

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.

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.

.
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.

.
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.

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.

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

.
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.

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

.
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.

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.

Our 4.2 GU Patrol was the same Roy.

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.

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.

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.

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 .

.
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.

.
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.

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?
Cheers,
Peter
OKA196 motorhome

.
Who are you asking Peter?

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......
Cheers,
Peter
OKA196 motorhome

.
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.

.
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.

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.
Cheers,
Peter
OKA196 motorhome

.
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..

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 : )))

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.

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

RMD,
Water at 21psi has a boiling point of 110C
My 118 C was a guess.

It is not "water".
Cheers,
Peter
OKA196 motorhome

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.

.
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.

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.

.
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?

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.

.
It's already too late Pete.

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.

.
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.

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

.
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.