I think i broke a piston ring, what now? :-(

[Nate Stuart]

Is your only basis for a broken ring the amount of burning oil??

If so I would defiantely do some more trouble shooting first, and
confirm or deny this before going any further, there are several things
on the engine that can cause copious amounts of oil to be burned up.

You could have a totally hosed valve guide seal(though these don't
usually put off _THAT_ much smoke.
    --Usually goes away when warm though, compression is generally still
on par.

Leaky seals on your turbocharger (I had a Renault with this problem that
put up an enourmous smokscreen at the stop lights).
    --Mine smeared oil all through both the IM and the exhaust, smoked
really bad when you stopped the car for a bit idleing, then when you
went to move again all rearward visibility was greyed out ;)

A plugged up crankcase ventilation system (My 90tq had a plugged up
breather tube this winter, and my goodnes the smoke that thing began to
pump out....).
    --Pop the oil cap off while the car is smoking if you get a big rush
of air out, thats a dead giveaway.

Or, of course you could have some 'broken' rings, or a piston with some
material missin'.
    --Do a compresion test across all 5 cyls, the one with 0 compression
is probably a good place to start

How is the car running? Are there hidious noises coming from under the hood?
I'm sure there are a coule other things that can cause similar
situations (head gasket for example).

Shooting in the dark at major engine work is a very time consuming
maintenance practice :-P

Oh, and don't go swapping the ECU's, your motor is most likely an MC-2
engine with higher conmpression, and 2 knock sensors. AFAIK the MAC 10
will want nothing to do with it without other work (Like rewiring your
ECU connector for example). Your MAC10 may run the engine, but it
CERTAINLY isn't running it as audi intended (Unless of course you have
an older MC1 motor, then this is much less a problem).

The two different pinouts are here,

MAC10/11 (MC-1 engines):
http://www.sjmautotechnik.com/pinout.html#ten

MAC14 (MC-2):
http://www.sjmautotechnik.com/pinout.html#fourt

What chip are you running? Do you have a stiffer wastegate spring in
there as well?

-Nate
'89 90tq
www.newtsplace.com/90tq


Britt Crowell wrote:

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>So my 1989 200 TQ started seriously smoking in Denver last night so I retrived today and got it home on the trailer.
>I assume that I have borken a piston ring(s). Its smoking very bad!!!! and its definately oil.
>So for you grus out there, how should I attack this? I'm thinking easy way is to get the intake and exaust manfolds off, head, oil pan and fix the broken ring with out pulling the whole engine.
>Or should I pull the whole engine and completely go though it?
>The car has about 185K miles on it.
>If i pull the engine should I do the clutch while im at it?
>How much money and time am I looking at here?
>Best place to get parts?
>I'm some sure will bring up othere questions that I'm not aware of.
>And also what could have really caused this? The engine does have the MAC10 and I'm running a 1.9Bar chip. I do drive it hard and I hit the fuel cut off last night too. I dont know why sometimes it does it and other times it dosen't. I really think its the MAC10 because the other car that box was in would do it to some times.
>Only had the car for about a year, and when I got it I had to fix the melter wireing harness from the rad. fan.
>???? a little help please ????
>
>Britt
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