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Re: New Radiator?? on a '90 V8


>A week ago my '90 V8 suddenly overheated.
>This car has always run on the cool side of normal (like ~90C) and then one
>day while motoring at about 45 MPH BAM! the needle all of a sudden climbs
>straight toward 120C and I drive for the shoulder.  There's a little water
>sprinkled around the neighborhood of the water pump... and the beast seems
>pretty warm... so I had it flatbedded 25 miles to the dealer in Seattle.

>From my experience temerature can change so suddenly and dramatically in
a few cases:

1. Thermostat is failed and blocks cooling system. Its easy to find -
lower pipe from radiator to water pump will be cool. It is worth
to check even if you have being told that it is OK.
2. Head gasket fault. Hot gases from the engine is going into cooling
system warm it up and creating a vapour blocks. In this case you can find
trace of cooling liquid in oil or air bubbles in cooling liquid when engine
is working.
3. Vapour block in cooling system. It is more difficult to determine.
But thanks to physics vapour blocks are always at the upper part of
the cooling system. If you can open cooling system there and wait until
air will go out (if it is there:) cooling system will operate again. But
then you will have to find where air is coming from - faulty gasket, small
hole in pipe etc.
4. It can be cooling fan fault but only at hot day and slow driving.

As for radiator I've never heard about such cases and can not believe that
you have so many dirt in the cooling system to plug it up completely. I
think it is worth to check everything else before going to spend this money.

With best regards

Audi 80 Quattro '85