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

Britt Crowell britt at fortcollins.com
Mon Mar 31 12:47:33 EST 2003

I'll clarify some things. I know that the computer was a MAC10/11 in the
car. When I fixed the burned wiring harness I couldn't get it to start and
found that I had a bad driver in the computer for the fuel pump. I snagged
the computer out of my 88. I know for sure its not a MC-2 engine. Not sure
what chip was in the other one. It came with my 88 that I still haven't
replaced the slave cyl in yet. It also had the 1.7Bar spring in it. I got
the 88 from Brad in Parker. (two turbos no limits! :-p )

Ok the smoke! Its a lot of smoke! I mean a lot!!!!!!!!!!!!! You don't want
to be standing around this thing when its running, I'm sure my friend that
helped me get it on the trailer has cancer from it now. Sat night the cop
that gave us a ride to my friends house said he had no clue where I was, he
just followed the smoke trail. I mean it was really huge!!!!!!!!! I can take
a picture of it idling if it would help.

It seems to crank just fine, and run well. The short distance I drove it sat
night in to a parking lot I noticed no problems. Or yesterday driving it on
to the trailer, such as total lack of power.

I'll go pull the plugs . Ok plugs pulled, they looked ok you can see a pic
and there is a pic of how much it smokes idling at about 2k rpm
I'm really hoping a turbo RnR is going to be all I need.

Let me know guys, This is such a great list and great help!

Britt Crowell
Crowell Consulting Inc.

----- Original Message -----
From: "Nate Stuart" <newt at newtsplace.com>
To: "Britt Crowell" <britt at fortcollins.com>
Cc: <quattro at audifans.com>
Sent: Monday, March 31, 2003 7:00 AM
Subject: Re: I think i broke a piston ring, what now? :-(

> 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
> 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:
> >This is a multi-part message in MIME format.
> >--
> >[ Picked text/plain from multipart/alternative ]
> >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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