Technical Over heating

[PuntoMills]

I have a 2000 W reg Punto 1.2 8v and it has been running fine until recently, the problem is the engine temp runs at half way when driving which is fine but as soon as I hit the slightest traffic and have to stop the temp immediately hits the red, the fan has been kicking in fine an frequent as always but the temp has never gone this high. What could be happening.

 

[benny279]

A few possibilities:

A. Possible airlock in the cooling, which will require bleeding, air in system means there could be a leak somewhere, so air gets in that way, you will need to pressure test the cooling system to see if any leaks are there. But bleeding may solve it.

B. Thermostat getting stuck at certain temperature, a replacement thermostat will be needed if old one is failing.

C. Low coolant? Top it up and check it in a few days if it drops again, you have a leak somewhere, which as A states, you will need to pressure test the system to identify where the leak is.

D. Possible water pump failure.

E. Possible temperature sensor failure.

F. The worse one, possible sign of headgasket failure! You will need to do a compression test on the HG to see if it's going or not if it is, then it'll be time to replace HG!

It'll one of those I'm sure, but if I've missed something I'm sure someone else will add to my post

DO NOT continue to drive while the car is overheating, if it goes past the halfway mark, switch off allow the car to cool down before continuing your journey!

Benny

 

[Brendan W]

I would change the thermostat while I was figuring out what to do by which time it would probably be sorted. Sounds like it's sticking part closed.

 

[benny279]

If changing the stat remember to bleed the cooling system afterwards.

Benny

 

[Davidireland]

No one mentioned the fan motor. They are the usual suspects for failing and causing the headgasket to blow.

 

[atom0007]

No one mentioned the fan motor. They are the usual suspects for failing and causing the headgasket to blow.

OP says fan kicks in fine...


You could have a restriction somewhere in the cooling loop, but that's just speculation.

 

[Davidireland]

Oops you are dead right. Sounds like a thermostat problem then. Unlikely a temp sensor as there would be fuelling problems and management light on.
Also a blocked radiator can cause those symptoms.

 

[benny279]

I just listed most culprits from top of my head, so nothing was ruled out, but i'd agree on thermostat i had similar problem and it was thermostat, but it is always best to check other things out like for any leaks etc while your there putting a new stat on, i did a pressure test on my system before and after for that extra reassurance

(For pressure test, I was lucky a friend of mine had one to borrow me )

Benny