heater control valve

[David Head]

On the V8 this vacuum controlled valve is moved from the engine
compartment to the heater box area (under the 'water box cover') next to
the blower fan. It receives much less external heat from the engine in
this position and is less apt to fail. That being said, on a 10+ year
old car I would replace it anyway. After that, you should have no
worries. They aren't expensive (15-30.00 depending on your source) and
pretty simple to replace.

These valves are a high failure item on the I5 engines. Their location
between the engine and firewall subjects them to high heat cycles over
years and they fail by splitting in half. BTDT twice. Its impressive.
You lose coolant so fast the guage won't register an increase until the
steam hits it (about 15 seconds or less)... Any Audi owner that gets a
high temp warning should immediately pull over and check their coolant
level. Waiting 30-45 seconds can lead to engine failure or a blown head
gasket... If this occurs, allow the engine to cool completely to ambient
before adding water/coolant. Adding coolant to a severely overheated
engine can cause more damage that the original overheat, not to mention
the possibility of injury due to scalding water being hurled back at
you.

John Dodd wrote:

>
>
> I am a new owner and I have no idea about this problem.Where is this
> valve and how often should it be changed ?
> Thanks
> John