flashbang said:

I will probably monitor the situation for a while to see if it still overheats. I was quite convinced the symptoms were for a stuck half open thermostat. No way an extra 500ml of water could solve that. Perhaps it magically unstuck itself?

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I monitored the situation over 3 days of driving and it no longer overheats. I did notice that it does take a while for the temperature gauge to get up to the middle mark.

flashbang said:

I monitored the situation over 3 days of driving and it no longer overheats. I did notice that it does take a while for the temperature gauge to get up to the middle mark.

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depends what temp it is outside but it should warm to middle in up to 4 km of driving from cold engine

flashbang . No, it will still be stuck partially open. It needs replacing

Twotoncarman said:

flashbang . No, it will still be stuck partially open. It needs replacing

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I noticed during the first 5-10 minutes of driving, occasionally when stopping at the traffic light, the temperature needle can drop 1-2 boxes. It goes back up again to its previous position upon moving off. After a sufficient amount of driving, the temperature needle stabilizes at the middle mark and no longer fluctuates around.

Only difference is that I have added in that 500ml of water.

I would like to test the thermostat but I have no tools and I am afraid I will not be able to put everything back together. Given that 1 week ago I didn't know what a thermostat is or how the car's cooling system works, I'll pass on any mechanical work on my car...

flashbang said:

I noticed during the first 5-10 minutes of driving, occasionally when stopping at the traffic light, the temperature needle can drop 1-2 boxes. It goes back up again to its previous position upon moving off. After a sufficient amount of driving, the temperature needle stabilizes at the middle mark and no longer fluctuates around.

Only difference is that I have added in that 500ml of water.

I would like to test the thermostat but I have no tools and I am afraid I will not be able to put everything back together. Given that 1 week ago I didn't know what a thermostat is or how the car's cooling system works, I'll pass on any mechanical work on my car...

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I assure you the thermostat is faulty.
Take it to a garage and have it changed if you do not want to do it yourself.

Twotoncarman said:

I assure you the thermostat is faulty.
Take it to a garage and have it changed if you do not want to do it yourself.

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He lives in Singapore. The A/C is on all of the time and so the fan must be on nearly all of the time. If the thermostat was majorly faulty in a partially open position and the fan is going nearly all of the time it is hard to see how the temperature would still be correct.

Strange as it seems there does not appear to be a fault worth bothering about at this stage.

judderbar said:

He lives in Singapore. The A/C is on all of the time and so the fan must be on nearly all of the time. If the thermostat was majorly faulty in a partially open position and the fan is going nearly all of the time it is hard to see how the temperature would still be correct.

Strange as it seems there does not appear to be a fault worth bothering about at this stage.

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Why is Singapore of relavance ?
Anyway. A partially stuck thermostat would cause exactly these issues. It is actually NOT difficult to 'see' the issue. A slower warmup, and overheating when slow and hot. The cooling system has a lot of backup built in, but eventually will cause the gauge to climb when stressed.
It is a simple and cheap thing to change.
A stitch in time etc etc.

Twotoncarman said:

Why is Singapore of relavance ?
Anyway. A partially stuck thermostat would cause exactly these issues. It is actually NOT difficult to 'see' the issue. A slower warmup, and overheating when slow and hot. The cooling system has a lot of backup built in, but eventually will cause the gauge to climb when stressed.
It is a simple and cheap thing to change.
A stitch in time etc etc.

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This car 'in the tropics' no longer overheats and once the car has warmed up the temperature gauge remains on the correct mark without fluctuation.

The car now has 500ml of extra water in it so will take longer to warm up.

judderbar said:

This car 'in the tropics' no longer overheats and once the car has warmed up the temperature gauge remains on the correct mark without fluctuation.

The car now has 500ml of extra water in it so will take longer to warm up.

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The car no longer overheats until the weather gets hotter again and stuck in traffic...
An extra 500mL won't alter the warm up time as the thermostat SHOULD be closed during initial warmup... It is warming the coolant in the closed circuit.
No worries though, it certainly was not 500ml of fluid that made any difference. Wait and let it develop.

Twotoncarman said:

The car no longer overheats until the weather gets hotter again and stuck in traffic...
An extra 500mL won't alter the warm up time as the thermostat SHOULD be closed during initial warmup... It is warming the coolant in the closed circuit.
No worries though, it certainly was not 500ml of fluid that made any difference. Wait and let it develop.

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With almost no seasonal differences Singapore experiences a tropical rainforest climate, which remains hot, humid always. During the day temperatures usually stands 30°C, while nighttime temperature hardly falls below 23°C

The thermostat begins opening around 15C before the operating temperature is reached.

Actually I have started to notice that the temperature needle now rests 2 boxes below middle on long, uninterrupted drives in the night, during which the temperature on the multidisplay reads 28C. It goes back up to the middle when I stop at a traffic light.

I agree that it's strange that adding 500ML of water stopped the overheating. In the past week it no longer overheats when I'm stationary at the traffic light. Previously the needle would start to rise within 15 seconds of stopping. Perhaps the thermostat is stuck half open, but the extra water has somehow managed to keep the temperature within operating range? I can't really think of a good explanation for the current behaviour.

The workshop I visited previously quoted me around SGD200 (close to 100 GBP) for a thermostat replacement. Since it's holding out now I will cross my fingers and hope this lasts for another 12 months before I switch cars...

flashbang said:

Actually I have started to notice that the temperature needle now rests 2 boxes below middle on long, uninterrupted drives in the night, during which the temperature on the multidisplay reads 28C. It goes back up to the middle when I stop at a traffic light.

I agree that it's strange that adding 500ML of water stopped the overheating. In the past week it no longer overheats when I'm stationary at the traffic light. Previously the needle would start to rise within 15 seconds of stopping. Perhaps the thermostat is stuck half open, but the extra water has somehow managed to keep the temperature within operating range? I can't really think of a good explanation for the current behaviour.

The workshop I visited previously quoted me around SGD200 (close to 100 GBP) for a thermostat replacement. Since it's holding out now I will cross my fingers and hope this lasts for another 12 months before I switch cars...

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28C? it should be like 76-80 while car is warmed up

Hi
The thermostat is definitely stuck. I changed the bride's Punto 2 weeks ago for exactly the same issue. Symptoms were identical. The 'stat is rated at 31 (87f)
You wont have any issue unless in heavy stop start traffic and the outside temp is high. If the system pressure goes over 1 Bar it will vent again, losing more fluid.
£100 is ridiculous for the thermostat replacement ! I can see why it would be avoided lol.
Best of luck with it. fingers crossed

didnt even see that he wrote that they would charge 100 squid to change thermostat LOL!
thats one of the easiest things to do

https://www.fiatforum.com/punto-mk2-2b-guides/348260-thermostat-change.html

flashbang said:

Actually I have started to notice that the temperature needle now rests 2 boxes below middle on long, uninterrupted drives in the night, during which the temperature on the multidisplay reads 28C. It goes back up to the middle when I stop at a traffic light.

I will cross my fingers and hope this lasts for another 12 months before I switch cars...

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Failed thermostat it is then.

In case you do not know, you are driving a car which has a reputation for a failing head gasket where overheating is a likely cause of head gasket failure and the two part design of the top part of the engine makes it a right pain to change the head gasket, therefore more expensive, and if the head gasket fails it possible you will also need skimming of the metal surfaces to stop the gasket from failing again.

I suggest you get a quote to change the head gasket on a mk2b punto and another quote to machine the metal surfaces.

Edit: Just saw your other post about you getting an incorrect overheating message appearing on the dash which made me think you might have a grande punto??

flisko said:

28C? it should be like 76-80 while car is warmed up

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I think it's the one that tells you the ambient temperature, not the engine temperature. Looks something like this (this one looks like a Grande Punto display though):


Honestly repairs for this car are slightly higher than average as it's 1) old and uncommon - most Fiats around are Grande Puntos/Bravos now, 2) it comes from Europe. If you drive a non-Asian model of car, you typically get charged higher for repairs to the same parts. Quite unfair but that's the market over here and being a total mechanical noob I have to accept what the market offers...

It's really awesome to have so many guys on this forum who know their way around cars and are willing to offer their advice. Hopefully in the future I'll get some courage to try some mechanical work on my future cars It doesn't make much financial sense to get this one fixed up properly so fingers crossed nothing goes wrong.

By the way, I checked around online and a head gasket replacement would cost me close to 400 quid :bang: