2007 Audi A4 1.8T over heating probs

[Ppsa4]

Hello guys, am new here so please be gentle. Also sorry for the jump on and question straight away.

can anyone chuck any light on this, the car over heated a few days ago so called the AA who diagnosed a faulty thermostat. On their word I purchased and replaced the part. The guys who replaced it said he bled the system and topped it up etc.

Took the car for a drive locally and all was fine, so I ventured further out and noticed when accelerating to 70mph the temp would go up but then come back down when I slowed.

When I open the header tank cap the water bubbles up and over flows, have also noticed a clicking noise coming from the area of the thermostat and can also see the return pipe twitching when it clicks.

please somebody shed some light and helppppppp.



many thanks guys

[petrolbloke]

What make thermostat did you replace it with?

I have heard of thermostats being faulty from new, even genuine ones.

[Ppsa4]

Oh really, to be honest it did cross my mind. Not sure on the make but it wasn't no eBay jobby. Got it from euro car parts.
It's been suggested that it may be the head gasket but I ain't so sure.
Paul

[550Anniv]

.... I suspect water pump failure. The pump uses a plastic impeller to push the coolant around that is glued onto a metal shaft. The glue breaks down and at high engine speeds the impeller spins on the shaft.
When you slow down the impeller catches up with itself and starts pushing the coolant around the engine.
You will need to sort this out ASAP or you will cook the engine.

[Ppsa4]

Will get it booked in straight away. Thanks for your help guys

[petrolbloke]

Water pump is a good shout actually and is quite a well known problem, not sure why I didn't think of that before.

If it does turn out to be the pump, then it would be advisable to get a new cambelt kit fitted at the same time.