Hello all,

I have an '89 200 Quattro that is building pressure in the cooling system before it even heats up.

So much to the point that it is blowing out the relief valve on the radiator cap pretty much right when you start to accellerate moderately. So much that I have to add coolant every 60 miles or so.

I have not noticed anything resembling water in the oil, nor oil in the coolant. No white or blue smoke at all.


I should mention:

Replaced the water pump, the pump we replaced it with had narrower teeth than the rest of the gears on the timing belt.

I replaced the radiator cap, still has same problem.

There is no thermostat installed, which I found out 5 minutes ago while attempting to see if the thermostat is seized.

It is running straight water in the cooling system now, because I am not made of money.

The turbo was modified by a previous owner.

Does not seem to have lost any power, but runs rough sometimes.


Any ideas?

 

...
get a thermostat in there. for real.
i can bet that will fix your problem..
why the heck is there no thermostat???

 

A thermostat will not fix the problem, but it surely would be better for the engine because without thermostat it won't reach the estimated operating temperature ;-)

If the exhaust gas gets into the cooling system or the water gets into the engine your head gasket is blown. So I'd check the following:
- When you screw off the oil cap or remove the measuring stick, do you see a lot of white water/oil-emulsion?
- When you remove the radiator cap, does the water smell of exhaust gas?