Overheated - Bugger it.

[Slyjoe]

Hi guys, need your collective thoughts. We bought a real nice 98R 1.8 A3 55k on the clock, had the cambelt changed at a local garage as a matter of course just 2 days ago. The bastid overheated tonight - temp went up to 120 but we had to do a mile or so like this as we were in the middle of nowhere with the kids.
Any thoughts on what might have gone, and what might have been broke after driving it hot for 10 minutes
Thanks in advance all.

Edited by Slyjoe on Sunday 11th November 10:50

[phumy]

Did you also have the water pump changed at the same time? These have a tendency to let go after a while, something to do with a new design of plastic impellers. Its almost a written rule now, when you get the cam-belt changed you also change the water pump and the idler roller too.

Possible consequences to overheating:

Head gasket blown
Warped head
Radiator damage (if its on its last legs)
Hoses (self evident)

[Slyjoe]

Not sure about the water pump, just had a look now and it does'nt appear to have lost much water at all. I'll give it a run and see.

[mk1fan]

What happens is that the water pump impella inside the system just disintegrates, it doesn't lose water from the system just stops pumping it round. There's no external sign of this - except the overheating.

Instead of fitting a replacement VAG item that is still plastic, fit a brass impella item from German Swedish and French.

This will mean taking the belts off again and renewing the engine mount stretch bolts for the engine mount that needs to be removed.

As for damaged cuased whilst driving the car as it over heats I agree with the list above.

ETA as your car is now nine years old this should have been the third belt change for the car. Replacing the water pump should have been mentioned on the two previous occassions and certainly this time. Who changed the belts was it a dealer or an indepedant?

Edited by mk1fan on Monday 12th November 15:23

[Slyjoe]

It turns out it was the pump impeller as stated, thanks guys. The garage is a trusted independant, and although not a specialist they knew to check the pump when they did the belts, and all appeared intact, they are doing me a cost price deal to fix it, so although i'm a bit naffed off its not too bad.
If any of the above have gone wrong how would they make themselves evident ie head gasket failure?

[mk1fan]

The impella is not something they can visually check as they just fail. If they were aware of the problem, imo, they should have given you the option as to changing it or not when they did the belts. Make sure they put in a brass impella'd item instead of a plastic one.

If the hoses, rad, head gasket got damaged then they'd be leaking coolant. The headgasket can fail and coolant can leak into the oil rather than into the cylinder or outside. You can spot this because the oil turns white like mayo. If the head has warped the head gasket won't fit and it'll lose coolant as well. The head will need to be skimmed or replaced.