Subject: Thinking of buying a '91 200TQ

[C1J1Miller@aol.com]

Paul R Luevano (PRL) wrote:
Just looking for some advice on what to look for in a '91 200TQ20V.  I've
looked at this car twice, and am very close to putting money down on it,
but I'm not sure of everything to check on it.

Things I know are wrong:  Only pulls 1.4 bar boost.
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CJM:  That indicates that the ECU is not activating the wastegate frequency 
valve (or the valve has failed).  Do a couple runs (best is engine fully 
warm, up a hill in fourth, pedal on the floor).  Pull the stored trouble 
codes (details on my site).
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 PRL:  
I know the car has a bad cat (can hear it rattle, confirmed by mechanic).  
Could the low boost be because of this?  
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CJM:  Many 200q20v owners have a similar rattle; it's usually not the cat, 
but a cat/muffler mounting or support issue.  There's a fitting for measuring 
the CO right after the turbo (before the cats) that can be used to measure 
backpressure in the system.  Scott Mockry's page gives some details, I think. 
 As I recall, you shouldn't get more than a few PSI of backpressure even at 
boost.
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PRL:
I could not get the AC to kick on, even though the seller said it works, low 
charge maybe?  Looks like a slight leek from the rack, but nothing that would 
need attention anytime soon.
What else should I check?
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Check the A/C compressor area... is it covered in dirt?  possible leak at the 
fittings on/around the compressor, spraying compressor oil which then 
collects dirt.  Sometimes you can fix the leak by tightening the fittings... 
if the charge is low, you should pull the fittings and replace the o-rings.
Start the car, and set the climate control at "LO", in auto (or any mode but 
econ).  Watch the face of the compressor to see if the clutch engages.  If 
not, there's probably a trouble code stored in the digital climate control 
memory.  Bentley has about 70 pages for troubleshooting this system; a bit of 
it is reproduced on my page.  There is a low-pressure shutoff switch under 
the black plastic plenum behind the firewall that keeps the compressor from 
engaging when the system pressure is too low.

Racks are pretty trouble free on this model, unless the wrong fluid has been 
used.  A rebuilt rack with lifetime warrantee is available for somewhere 
around $250, plus a half-day labor in your garage.  Usually if the rack 
leaks, the bellows fill with fluid (feel firm, not empty).

You need to bring the car to a mechanic who's familiar with the type 44.  Put 
the car on a lift; do the basic checks on accident damage, fluid leaks, etc.  
Check all the rubber bushings front and rear.  Do a compression or leakdown 
test, and check the plugs.  Check the battery and charging system.  Download 
the stored trouble codes.  Check the front brakes (UFOs, or standard G60 
conversion?).  When was the timing belt/waterpump/idler pulley last changed? 
(60k interval, or more often if seldom driven).
You didn't state mileage, condition, etc... likely expect it will need a new 
hydraulic pressure accumulator (aka "bomb"), new strut inserts, some new 
suspension bushings, possibly a battery, ...
There's a Type 44 (meaning, 5000/100/200 and V8 from around '85-91) FAQ on 
the web; don't have the url handy, sorry, but it's in the archives.
More info on my 200q20v specific site:
http://members.aol.com/c1j1miller/index.html
and on Scott Mockry's turbo audi site:
http://www.sjmautotechnik.com
hth, chris miller, windham nh, c1j1miller@aol.com