89 200 Turbo SAGA goes on ...

[Cat ^. .^ ~]

LL - NY wrote:
>Fay,
>
>One thing to consider while looking for a boost leak would be
>to use the "boost gauge" function of your trip computer (see
>your owners manual as to how it functions if you don't already
>play with it. Just pay attention to the driving while you play with
>it if you're on the road, it can be quite distracting!). If the car is
>functioning totally correctly, if you are hard on the gas, especially
>at higher speeds (such as accelerating up an steep highway hill,
>don't know if you have those in Flagstaff), you should see 1.4 

only goes to .7 for the most part

maybe 1.0 for a nano second

>on
>the gauge and hold as long as you hold the pedal down. 
>If the computer is holding back some boost, (don't
>recall the all of the conditions for that, although one of these 
>conditions is a non-functioning WGV, see previous posts on that)
>it'll go to 1.2 and hold.
>
>BUT, if you have a fairly substantial intake system leak (like
>a bad MM (ribbed) hose or lower intercooler hose) you may
>end up with 1.1 or less, if the leak is QUITE severe, it will have
>a hard time staying at 1.0 (which means the engine boosts until
>it reaches outside air pressure (1.0 atmospheres), then the rest
>of the boost leaks away, but the engine is expecting more). 

yuppers, that sounds like it !

>Now, two places to check for leaks not mentioned:
>
>1.  Lower Intercooler hose. The large about 3" diameter J-shaped hose
>    that runs from the bottom right of the intercooler (radiator
>looking thing with
>    ribbed MM (for Michelin Man) hose that runs to the top right of
>it, directly
>    from the engine) to the turbo-charger. They are VERY thick rubber, so they
>    can sometimes fail, but look intact, and their thickness lets them
>fake integrity
>    for a long, long time, (like 16 years). When I finally replaced
>mine, it was
>    cracked through 3/4 the way around, and yet the car still ran (not
>super well,
>    but it ran). Fixed the car. It's NOT cheap (around $120 about 2
>years ago), and
>    is likely a dealer only part, but you need to remove yours in
>order to find out
>    which of the two types your car has. One is three pieces with a hard plastic
>    pipe in it, the other is a single piece rubber hose. BTW, this
>hose is a pain to
>   get to, easiest to get to if the front bumper (easy to remove) and
>grille, are
>   removed from the car. 
>
>2. The intercooler itself. The intercooler has an aluminum center
>section (core) and
>    plastic end tanks, which are crimped to the core. With time, the
>crimps can fail
>   and there is leakage at the end tanks. But, you ask, how can I tell
>that air is
>   leaking into ... air? 
>   Easy, because there is a notable amount of oil mixed in intake
>tract air (don't
>   really know why, anyone? Bueller?), wherever there are air leaks, there are
>   oil leaks. Feel the intercooler on the bottom, especially near the
>end tanks.
>   If there is oil present, there is likely a leak. 
>
>HTH,
>
>LL - NY
>
>
>On 6/7/05, David Conner <conner at cfm.ohio-state.edu> wrote:
> > Fay asks...
> > "Are you saying it is the Turbo which is not working."
> > 
> > Hi Fay,
> > No, that's not what I'm saying.  What I'm saying is you have a 16 year old
> > Audi with a turbo attached to the engine.  Turbos create a >lot< of extra
> > of heat and stress under the hood.  Your car likely has multiple problems.
> > Maybe a single one is causing it not to start, but there could very well be
> > a number of poor electrical connections, etc that are degrading performance.
> > 
> > Compared to a non-turbo engine there are more electrical sensors, wiring
> > and hoses under the hood.  The turbo generates an extreme amount of heat
> > which takes a toll on hoses, wiring, plastic, and everything else under the
> > hood.  The turbo creates a lot of >pressure< in the air intake system which
> > will cause failure of age/heat weakened components (hoses).  The heat
> > stress can also lead to a cracked exhaust manifold.  Leaks or cracks both
> > result in vacuum leaks which cause poor running or no-start condition.  The
> > turbo pressure >will< blow off a hose if a clamp was accidentally left too
> > loose.  (A hose clamp could accidentally be left loose by even the most
> > competent and honest mechanic, BTW.)  Access to many of these hoses and
> > clamps is difficult and some are impossible to see.  Even if you can see
> > the clamp, maybe you can't reach it.  A loose clamp may not >look< loose.
> > You had a recent timing belt replacement... this would require removal of
> > the intercooler and attendant hoses.  One of these clamps that you can
> > barely see, let alone reach, may be loose and later the hose blew off.   A
> > non-turbo engine does not have an intercooler and does not blow the hoses
> > off or rupture old hoses the way pressure form a turbo will.  Another thing
> > on the turbo engine which may have been disturbed during timing belt
> > replacement is the wiring/connector for the intercooler temp sensor.  If
> > the fragile little wires here are damaged they will short out this sensor
> > and rob your engine of power.
> > 
> > Did your car spend years in the rust/salt belt?  If so, this creates more
> > problems.  Sixteen years of high underhood temps causes deteriorated wire
> > insulation and connectors.  A poor connection on a single sensor is a
> > problem.  Cracked wire insulation and hardened rubber wiring connectors
> > allow salt to enter and corrode the electricals.  Access to some of these
> > sensors and wiring is difficult.  You cannot afford to replace all the
> > things on your car that could cause problems in hopes that one of these
> > things will fix it.  A methodical approach is needed where a problem is
> > narrowed down to it's source and dealt with.
> > 
> > Let me give an example from recent experience with my own 89 200Q that
> > improved performance...
> > The real problem which prevented the engine from running was a loose clamp
> > on one of the intercooler hoses... one of the clamps that is hard to see
> > and difficult to reach.  No doubt it was me who failed to tighten the
> > clamp.  When I tested for spark it appeared to be either no-spark or weak
> > spark.  I narrowed the problem down to the coil so I removed it to swap a
> > known good coil to see if that would help.  It didn't help because my
> > >real< problem was a loose hose clamp.  I examined the old coil and found a
> > surprise problem which I suspect is common on these cars.  There is a fat
> > wire connector pushed on to the bottom of the coil.  I pulled this
> > connector and found >way< too much green corrosion on it.  This wire
> > connector would be difficult to examine without removing the coil from the
> > car, and coil R&R is not easy, so I had never examined it before.  The
> > rubber connector boot here is supposed to seal out water but was hardened
> > from old age and no longer doing it's job.  I cleaned up the corrosion,
> > smeared di-electric grease around the rubber bootie and re-installed it in
> > the car.  Still no start.  Then I found the loose hose clamp and tightened
> > it.  Now the car not only starts and runs, but it starts and runs much
> > better than before.  So... I had two problems... one which prevented the
> > engine from running at all (loose hose), and a second one which caused weak
> > spark and reduced performance.  In the end I didn't install a single new
> > part, but having some known good spares to swap was a big help. I also had
> > plenty of time to troubleshoot at my leisure since I have a spare car to
> > drive at all times.  Replacement of the coil with a new one, a $200-250
> > part, would also have fixed the weak spark.  If I had paid a competent
> > honest mechanic to fix my weak spark I would expect it to have cost at
> > >least< $300, maybe a lot more.
> > 
> > HTH,
> > Dave C.
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > _______________________________________________
> > quattro mailing list
> > quattro at audifans.com
> > http://www.audifans.com/mailman/listinfo/quattro
> >


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