golf tdi overheated once, puzzled!!!!!!

[dainott2105]

Hi all, i have a leon cupra but my mate has just bought a mk4 golf tdi 115bhp with a full vw service history about a week ago. It has been perfect since he had it until last night when coming down a dual carriageway (doing about a ton) and the temp gauge suddenly went up to 130 and the red warning light came on. I said to put the car into neutral and coast and the temp then started coming down, so first thought was water pump as it had gone on my leon a few months ago with the same symptons. I was expecting the temp to go back up when he put it back into gear, but it didnt and the temp has been fine since!!! (he has done about 30 miles today and has put his foot down a few times). I cant make head or tail of this one (timing belt was changed 7k ago and he is going to confirm that the water pump was done) and there was no loss of coolant. I dont know if a faulty coolant sensor would make it do this, so anyone got any ideas about this one.

PS sorry for the essay lol. Any help greatly appreciated

[godfried]

Might have been that the thermostat got stuck by gunk/scale in the cooling system.

[besian]

respect your engine :zx11:

it is very likely the cooling fan not working. on mine it was working fine when there was good weather but for unknown reasons when it was raining in would fail to switch on so at times i went out open the front bonnet and started manually the fan. other times when i could not stop due to traffic i switch on heating and open windows as result the temperature gage would go down.
your friends engine would have a short life if it runs when overheated and second hand one cost around 900 quit

[dainott2105]

Besian not quite sure what u meant by saying respect your engine (not sure if you are having a go at me there) but i do respect my engine and my mate does too!!!

Thank you for the replies though and i will check if the fans are coming on and get the thermostat checked (will it show up up on vag-com mate?).

The problem has not happened since and the car has been running perfectly. Going to get it on Vag-com asap and think its work changing the temp sensor if it hasent been done. Problem for my mate is he is trying to find out from another dealership exactly what has been done on the car in the services, but this is a really strange issue. Cant be water pump cos it would still be overheating under load. Its not loosing any water and is running fine again now.

[mluton]

I hope you meant 100km/h. LOL

I agree with the above, get a scan done first, it could point to the source of the problem.

[dainott2105]

yea il get it scanned asap. Is the temp sensor the same on the diesel as the petrol folks in terms of part and location?