89-90 200TQ, MC engine, Clicking noise

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

Hello,

I finally purchased a QUATTRO!!!!!! I just got an 89 200TQ with 75K miles. WOW, this car
is much better balanced than my previous FWD 86 5000CS Turbo. Duh! , no kidding it's a quattro.

>Ken Bell asked about a clicking noise.........
The clicking noise on the 89-90 200's that starts shortly after the engine is started comes from a 
solenoid that is used to vent fuel vapors into the 10V Turbo engine. The clicking noise is pretty
loud and is almost as loud as  a typical 5 Cyl noisy hydraulic valve lifter. The clicking is normal.

From: Michael LaRosa 

Subject: Re: 100 vs. 200 vs. 80 vs. 90
>On the 89 200s you have a choice.  If you plan to upgrade the engine

>look for engine code MC in the underside of the trunk lid.  This is

>the lower compression engine which lends itself to more boost 

>upgrades.

The 89-90 10V Turbo engines with the 8.4 to 1 compression (instead of 7:8 to 1)
and dual Knock sensors are  still designated as MC engines.  

The factory Audi service publication "1989 Model Change Information" indicates a change was
made to this MC engine to increase the compression ratio to 8.4 to 1, use a new ECM with dual
knock sensors, and smaller turbo for better low end response. 

My car has the newer dual knock sensor engine and the smaller turbo but still has the MC 
designation.

I talked to Ned Ritchie and he indicated that you can raise the boost on these engines up to 14 psi
without any problems but did not recommend going above that. The earlier 10V motors with
7:8 to 1 allow more pressssssssssssssssurrrrrrrrrrrrrre.  Check with Scott (PDQSHP) for
more details. Scott's cars have been seriously modified...................and have mucho HP.

Scott M.