1989 vs 1990 200 TQ and Timing Belt Issues

[scott.john.mockry@bangate1.TEK.COM]

Hello,

As Scott (PDQSHP) mentioned there were some  mid 89  model year changes made to the 
"MC" designated engine for the 200TQ cars. Keep in mind that the actual "production" dates 
(shown on the  drivers side pillar) for the 89 model year cars start around 6/88. I recently 
bought an "89" 200TQ that has the later MC engine with dual knock sensors, smaller turbo, 
different computer (MAC 14C I think), different camshaft etc. that has a production date of 
12/88. One way to tell the earlier and later engines apart is to look on the firewall where the 
connectors are mounted for the knock sensor(s),  and the two crank/flywheel  sensors. 
The later model  MC engine will have 4 connectors versus the 3 connectors on the earlier MC 
(single knock sensor connection).  You can also look for the second knock sensor mounted toward 
the rear of the engine block. 

The factory training service book (89 Model year changes) indicates that the engine has more 
low end torque but the same HP output.  I looked at another "89"  model year 200TQ with a 6/88 
production date that had the earlier MC engine with single knock sensor, larger turbo, and lower 
compression. It did not seem very smooth or refined, but it may have been abused  by the
previous owner (it had 90K miles on it).

The Timing belt was also changed on the these MC engines in 88-89. The newer timing belt has
teeth that are rounded and of course it costs twice as much ($60 from the dealer) than the earlier 
timing belt for the 84-88 1/2 5000 cars. This would also indicate that the water pump, crank
and cam gears would be different as well. The valve cover gasket for these cars is also 
slightly different. 

I would recommend bringing in your VIN number any time you get parts for  these 89 200 TQ cars.
 I read in one magazine review that the 89 model year vehicles have  around 1500 new parts. 
The newer style interior with Air bag etc. must account for a large  portion of these 1500 parts.
A technician I know that works at the local Audi dealer said the only change he could think of
that occured  in the 90 200TQ was a different type of wood used for the dash, something that 
was apparently not on the endangered species list. One of the Audi service bulletins indicates 
that  the wood trim finish process was improved in 11/89 to eliminate the cloudy/milky 
appearence that shows up in these cars. I would imagine there are other subtle changes as well
on these 1990 model year 200TQ cars. Does anyone know of any other differences between the 
89 and 90 200TQ's ?????

Scott M.

>PDQSHP said

In late 89 (89 1/2) the 200 turbo went to a higher compression motor (8.4:1

from 7.8) a different engine management computer with dual knock sensors, a

different cam, different IC design......   The baseline power gives the

"smooth" feel, but the 5 is the same, just pieces parts......  If you jump a

tooth on the cam of the "older" cars, the difference is much harder to

notice.....



Scott