Re: Overhot VW

[Greg & Britt <image_one@earthlink.net>]

Scott Chaney wrote:
> 
> Well, now that I have gotten the answer to my Audi question, I'll ask
> my VW question(s). My Quantum (88 5 cylinder) tends to run hot all
> the time.

This is extrapolation from my Audi experience, but since the systems are
very similar here it goes.

Make sure all fan speeds are working ,you will either have 2 speed or 3
speed. The low speed tends to quit more often because of greater use of
that circuit.
I have also had problems with the fan speed thermostat in the radiator
change its operating point, not turning on until it‘s very hot.

Cooling system flush time, it seems that the use of non-recommended
anti-freeze causes excessive corrosion in Audi/VW cooling systems,
specially the radiators, causing cronic overheating.

Had a water pump suck air past the seal causing cavitation in the pump,
it never leaked coolant at the pump!! Lots of ”burping” out the
expansion tank.

The lowly thermostat. After trying many aftermarket replacements I’ve
found that the OEM one works the best. If you look closely at it you’ll
note that it is actually 2 thermostats built together.  It changes flow
direction inside the engine block. Pretty clever them germans. A bit
pricey though.

> and it also seems to be labored when sitting at traffic lights, etc.,
> (A lot of engine vibration seems to be transferred to the passenger compartment.

Welcome to the Audi rumble, very common at certain idle speeds, A/C on,
ect..you may have also lost the liquid in the engine motor mounts.
Audi/VW had a service bulletin advising replacement even if no obvious
fault was found with the motor mount!

GT

84 5KT
87 5KT