[Gannu_1]

I’ve noticed that for most cars, the coolant temperature stabilizes at 90 ’C. Why is that?

The boiling point of the coolant is higher than 100 ‘C due to the additives added to plain water but wondering why it stabilizes at 90 ’C when the engine is running.

[Jeroen]

Originally Posted by Gannu_1

I’ve noticed that for most cars, the coolant temperature stabilizes at 90 ’C. Why is that?



The boiling point of the coolant is higher than 100 ‘C due to the additives added to plain water but wondering why it stabilizes at 90 ’C when the engine is running.

As with any part of an engine, it is the result of different parameters that need to be taken into account. Cooling water temperature has a huge effect on wear and tear of the cilinder and piston rings to name one. But most likely it is just a over dimension or safety margin. You don't want to be operating to near to the boiling point even if that is higher then 100oC. If you find yourself with very high ambient temperature and high engine loading, e.g. Going up a mountain, you might see the needle creeping upwards!

Jeroen

[petroguzzler]

Originally Posted by ajmat

Snapped Belt - Water pump is driven by a belt off the crankshaft. It also drives the alternator in most cases. If the charge light comes on and temp gauge rises, there you have it

Consequences of Overheating[/b]If you see the temp gauge rise and stop in time, all is forgiven - You will get away with it

If above + you hear the water bubbling - You have just got away with it

If above + water spewing in the water compartment - You might or might not have got a away from it

This incident happened to my Vista quadrajet. The alternator belt snapped and the charge light came on. The power assistance to the steering failed and the temp was at the H level. I stopped the car and on opening the bonnet I saw the water in the coolant storage bubbling and there was water spewing in the water compartment. We had it towed to the mechanic who then replaced a bearing of the belt that had snapped. It was clearly a case of the snapped belt causing the water pump not to work properly. Any ways after service, the mechanic advised me to continuously monitor the engine temperature as he said that he was not sure whether there would be any damage to the head gasket. The car drives fine now. Is there any way to ascertain whether there would have been damage to the head?

[VCheng]

Originally Posted by petroguzzler

This incident happened to my Vista quadrajet. The alternator belt snapped and the charge light came on. The power assistance to the steering failed and the temp was at the H level. I stopped the car and on opening the bonnet I saw the water in the coolant storage bubbling and there was water spewing in the water compartment. We had it towed to the mechanic who then replaced a bearing of the belt that had snapped. It was clearly a case of the snapped belt causing the water pump not to work properly. Any ways after service, the mechanic advised me to continuously monitor the engine temperature as he said that he was not sure whether there would be any damage to the head gasket. The car drives fine now. Is there any way to ascertain whether there would have been damage to the head?

If it is driving fine, with no problems with oil or coolant, you could just let it be. If you want peace of mind, just do a compression and leakdown test on the engine.

[Aksthedreamer]

Last evening my car suffered from this overheating issue, the coolant started overflowing and steam started to come out.
I checked radiator tank, car was running low on coolant. when the car cooled down, after around 40 minutes I filled the tank again with coolant and water, again the coolant leaked along with steam.
Then I left the car to cool down for a few hours, came back filled the tank with only water this time and drove the car, no steam no leakage and the temp needle also remained normal. Drove the car for arnd 2kms and reached home.
I am confused, why was there overflow and steam when the car was filled with coolant and water but no leakage when second time it was only filled with water?
What all do I need to check in the car for damage tomorrow morning?
First thing that I will do is, start the car and ac and see if the temperature needle rises again and if there is anymore leakage.
Just worried about the radiator, hope its not damaged.

[saket77]

Originally Posted by Aksthedreamer

I checked radiator tank, car was running low on coolant. when the car cooled down, after around 40 minutes I filled the tank again with coolant and water, again the coolant leaked along with steam.

I suspect the radiator cooling fan is not turning on. This can be a result of something as simple as a blown fuse or a relay to something like failed fan motor. You need to check if the radiator fan kicks in when temperature needle starts moving over half the mark on the gauge. Also, as you already know, overheating of engine can lead to irreversible damage to the engine, hence be very careful and get the problem attended to ASAP!

Regards.

[Aksthedreamer]

Originally Posted by saket77

I suspect the radiator cooling fan is not turning on.
Regards.

Checked the car just now, radiator fan working fine, although its the first time that I have noticed that the radiator fan turns on only when the ac is switched on. Is it supposed to work that way? My car is a 2006 chevy optra.

The water that was filled last night has leaked from the bottom overnight, filled it again to check, there is leakage from the bottom.
Any idea about the cause of that leakage?

Though I will take the car to my mechanic in a day or two, just wanted to get an idea about the problem as my mechanic is 17 kms away from my place, so not sure if I will be able to take the car there with this problem.

[::CMS::]

The steam or other issues were due to the burning of the coolant when it falls on the hot surface, thats why there was no drama when you used water, get the coolant leak fixed asap. Can you post a pic of the leaking portion?

[Aksthedreamer]

Problem solved, due to heat the hose pipe developed a gap, coolant was leaking from there, replaced it with a new pipe.

[tharian]

Saw the coolant temp touch 106c today in stop/go traffic.
The high temp warning did not come on. I turned off the AC when I saw it hit a 100 and it still climbed.
Did not hear the fan after turning off the AC., probably it was spinning at the low speed.

No changes felt while driving, but I was wondering how high is okay on the Ford Figo 1.2 engine

[mayankk]

Originally Posted by tharian

Saw the coolant temp touch 106c today in stop/go traffic.
The high temp warning did not come on. I turned off the AC when I saw it hit a 100 and it still climbed.
Did not hear the fan after turning off the AC., probably it was spinning at the low speed.

No changes felt while driving, but I was wondering how high is okay on the Ford Figo 1.2 engine

Is this normal, moving beyond the regular range?
What I thought was your system will do everything to keep the needle on the mid/correct temperature mark, and will succeed, no matter the traffic or temperature outside(unless you're driving somewhere where it's 75deg C.

In context, in my fiesta the needle never moves beyond the mid mark, it's usual haunt.
But, when it has, my head gasket went, and another time, my fan had conked off. So it'd be worth getting it checked right now, than wait for the next climb.

[tharian]

Originally Posted by mayankk

Is this normal, moving beyond the regular range?
What I thought was your system will do everything to keep the needle on the mid/correct temperature mark, and will succeed, no matter the traffic or temperature outside(unless you're driving somewhere where it's 75deg C.

.

I don't think it is normal. It was the first time I noticed it nearing and crossing a 100c.
Notmally it is at 95-97c. Yesterday I was in peak traffic for more than an hour when I saw this reading.
It reduced when I finally got some open road. Will keep a watch on it.
Also, if I remember on the Fiesta the temperature Guage has a figure mentioned on it for mid and max., could you tell me those numbers.

[mayankk]

Originally Posted by tharian

I don't think it is normal. It was the first time I noticed it nearing and crossing a 100c.
Notmally it is at 95-97c. Yesterday I was in peak traffic for more than an hour when I saw this reading.
It reduced when I finally got some open road. Will keep a watch on it.
Also, if I remember on the Fiesta the temperature Guage has a figure mentioned on it for mid and max., could you tell me those numbers.

I think it says 60 and 120. But I can tell you this, anyone it's moved beyond its regular spot, it has cost me. And when all has been well, it sucks to it's spot no matter what the traffic, though the fan worked overtime.

[ritedhawan]

I've long been aware of the indications that a car exibits that enable me to come to a conclusion that the car is Over-Heating, and pretty much aware what needs to be done to set up an improvised solution.

But, I never imagined the magnitude of damage that Hard Water can do to the car cooling system. A lesson well learned many years ago. I was accompanied with my Brother , In the Ist-Gen Tata Indica, from Manali to New Delhi. Under the afternoon sun, passing Bilaspur, we noticed one to many indicators that enabled me and brother know that the car is overheating, not to mention the temp-gauge. We had gone through a whole lot of broken roads, the front of the car had banked many times, interspersed with the 'thud' noise. The moment the car over-heated, My brother knew that water+coolant had leaked out, pop the hood,and small amount of steam belowed out, residual coolant around the pressure cap, reservoir completely dry, fortunately radiator fan is fine. Immediately, we switched the engine off, looked far and wide, no Petrol-pump, mechanic, or even a hamlet in the vicinity! Nevertheless, in front of eyes, stood a hand pump and a truck parked besides it, and a driver and his help, having a bath.They were drawing out water from the pump, bucket full, alternatively throwing it on themselves and then on thier truck! . As one hour elapsed, we filled up a 2 litre bottle with the hard water from the pump, and gradually opened the pressure cap with the help of a thick cloth, once that was done and radiator seemed completely dry confirming our suspicion that perhaps there is a leakage, turned over the engine, and gradually poured the contents of that bottle into the radiator, and refilled the bottle until the radiator filled to the brim and filled the reservoir.

We continued on our journey, within the first 10 kilometers, we stopped at the first Petrol-pump bought 2 Litres of coolant, popped the hood, and reservoir dry, again we used the 2 litre bottle and filled it up with drinking water and mixed a small part of coolant, and poured the mix into reservoir. The moment temp-gauge needle surpassed the usual point,We followed this routine--filling up the reservoir after every 10-15 km-- stopping at petrol-pumps, as evening turned to night the need to repeat that routine decreased , as a matter of fact, once we stopped at Karnal Haveli, had our late night dinner, came back, found out that there was no need to fill the reservoir.

We came back home, from the very moment we observed the issue till home, my brother drove the car gently, rare acceleration and de-acceleration, few throttle inputs, crusing as much as possible.

The next day, car brought to the attention of our prefered mechanic, the same evening , on our way back to our prefered mechanic to know the damage. We knew that radiator would have to be replaced. Well, our prefered mechanic infomred us, that not only the radiator would be replaced, the hoses that conveyed the mix along the circuit would have to be replaced, and was insistent that water pump would be replaced as well etc. He confirmed our suspicion that radiator was leaking, and during the flush-out, stated that brown-green mix was flowing out, along with brown residue! The brown residue must be the cause of concern, and could be the reason why so many things would have to be replaced.

We have come a long way, since those indica days, at that time, I didnt even know how to drive a car. But, had superficial knowledge of how things work under the hood, and so did my brother. Now, I drive a completely different Vehicle, and yet carry a carton full of drinking water bottles, in the trunk. Primarily, for drinking water, but who knows it may come handy, if one faces the situation again, and not to forget, 1 Litre of coolant as well!

[sudev]

2007 model Civic with 1lac km plus on odometer. Maintained at A S S to 80k and after that at FNG.

In last two weeks it has suffered a strange problem. Four times it has had temperature shoot up to red end. Thrice it was in bumper to bumper traffic but one time in reasonably moving traffic.

Every time radiator has shown coolant loss.

All times this happened I had air-conditioning on and set to moderate 24 degree.

Things done till now
1 Cleaned up radiator cores after opening top and bottom tracks
2 Did flush treatment
3 Checked fan operation
4 Checked radiator cap
5 Checked overflow pipe and tank for leakage
6 Replaced both hoses
7 Checked thermostat
8 There is no emulsion presence in mobile oil
9 No apparent leakage marks in engine compartment

Now apart from checking / replacing water pump what else could. I look at? Though there are no leakage marks around the pump area.

Fortunately till now engine has not seized.