Hello,

I bought a not so well maintained Punto 55s -99 in December and on and off its cooling system tries to out smart me...

Symptoms experienced during my 12.5 mile trip to my office:
1) On the first start in the morning it usually only fires upp 3 of the cylinders. The last one comes alive after ca 30s. It is clearly audible how the ignitions are ramping up from zero to fully functional.
2) After about 10minutes of driving, mist is coming up on the inside of the windscreen. This happens exactly when the interior heater is getting warm. I think I can smell a bit of glycol when this happens.
3) When I come to my office and stop the car the plastic expansion chamber (that with the cap) is usually empty. If I carefully unscrew it a bit I can hear a hissing noise and the water level rises. The water hose from the engine at the same time goes from stiff to spongy.
4) When I go back home the engine starts with only 3 cylinders but the fourth comes alive quicker than on the morning start.

Other oddities:
*When I first started driving this car I had problems with the interior heater blowing cold air when the engine was running at idle.
*I have never heard the fan running. But we have quite cold weather now, 5 to 23F, maybe this cools it?

I guess the above errors is due to a blown HG or some strange airlock.
What do you think could be the error?

sounds like the head gasket to me

classic head gasket symptoms , you can probably hear water gurgling noises from the heater .

sounds like the heater rad could be leaking too which is not an easy or cheap job. The HG is relatively easy to repair .

Thanks for the replies. I find it a little bit odd that the oil seems clean and that not much water is lost over time. But you are right, it all points to the HG being damaged. Guess it is venting gasses from the cylinder and OUT to the cooling system instead of the reverse.

I will try to keep the car until next MOT in December and sell it for scrap. Got it cheap so it's no big deal.

Yes mate sounds like HG, any deposits coming out of exhaust? Thick white smoke? water vapour like steam?

The HG on Punto seem to be a comman thing recently as more and more seem to be going! :bang:

The little basterd is actually working a little bit better now!

Did the following:
Poured in a bottle of Bars Leak in the system. Cheap-and-dirty-solution or desperate-as-hell-solution, same same.
The mist on the windscreen vanished to a minimum. But the pressure build up in the coolant system was still there.

Bought ANOTHER of those magic wonder cures: Wynns Cylinder block seal.
Followed the instructions and this one requires that you flush the system and use only clean water to fill it up again, then pour in the snake oil.

When doing this one of the steps was to remove the thermostat. This seem to be impossible on a Punto if you don't break up the thermostat a little bit, since the thermostat housing is a part of the piping. Anyhow, I noticed that some kind of rubber o-ring and debris seemed stuck in the thermostat. So I took a screwdriver and removed the whole spring, valve thingy. Of course everything landed in the bucket filled with old coolant that was sitting beneath the car, its a physical law. :doh:

Filled the coolant system up with water again. Managed to misalign the tapers on the upper bleed screw but got it tight anyway. :bang: Lots of brain smacking going around here... As a finish I added the Wynns stuff to the coolant expansion chamber. Drove around for about 10 min. Removed the sparkplug from the cylinder where I suspect the leak is. Drove around 5 min more. Don't drive around with removed spark plug on a car you care about... It smells and sounds bad. The catalytic converter probably took some punishment.

End result, no more pressure build up! Since the effing car lacks a coolant temperature gauge I don't know how cold it its (with no thermostat) but it gets hot enough to give a decent warmth inside. So this solves it for me. I can drive it to next MOT in November/December and then scrap it if it needs repair.