[200q20v] Any new tips for buying 1990 200tqa20v w/UFO brakes?

[Phil Rose]

At 1:48 PM +0100 11/17/01, Maurits Jonkergouw wrote:
>Hi, I'm new to the list and already searched the web for all kind of
>information on the late 1989 - early 1990 European 200tqa20v, and
>found many info including the usual 'watch out for...' and the UFO
>brakes, but I'm wondering if there are any other known problems for
>the 3B engine and relative parts to watch out for when buying a
>second hand one...  I'm going to see the car tommorow already...

The 3B engine itself is very reliable--assuming normal maintenance
was done. As with all Audis--timing belt replacement should be done
at close to the recommended mileage interval. The main "problem"
points related to the 3B would include items involving turbo
operation:

(1) the throttle overrun valve (known as "bypass valve") has a
relatively short lifetime, and when it's defective it will cause
sudden engine stalling when the throttle is lifted. Easy and
inexpensive to replace (under US$50). The vacuum hose connecting this
valve to the intake manifold is usually burned (from exhaust heat)
and prevents the valve from operating.

(2) The wastegate frequency valve will often be defective in a
high-mileage car, and this causes the maximum boost to be limited to
about 1.3 bar (a normallly operating 3B system should produce maximum
boost of 1.7-1.8 bar by 3000 rpm with wide-open throttle in 4th
gear). The valve costs about US$80.

(3) There is an afterrun water pump that is thermostatically
triggered to run after engine shutdown--to cool the turbo. The pump
is plastic and is prone to develop some leakage--sometimes a sudden
loss of all coolant. Check for signs of leakage. The afterrun cooling
system typivcally will function only during relatively warm weather.

Other "watch for" items are pretty typical of other Audis from the
late 1980s (power steering hydraulic pump/hose leakage, etc).

Phil
--

Phil Rose				Rochester, NY
'91 200q				mailto:pjrose at frontiernet.net