’91 760 Turbo, lack of acceleration, vibrates while idling

Hey all,

I own a 1991 760 Turbo Wagon, it’s got about 138K on it. To
preface, I’ve had problems with the exhaust being pretty thick, I’ve
tried some oil additives to clean it up but they haven’t worked all
that well. My mechanic says a small amount of oil is getting into the
exhaust somewhere along the line. Anyway, not sure if its related, but
in the past month or so I’ve noticed the car shaking a little bit when
I’m stopped in traffic. The past couple days the shaking has gotten
significantly worse, and now continues for a few seconds while I’m
accelerating. It feels like a damn airplane taking off. To top it off
the acceleration is terrible now, and the engine seems like it takes
forever to kick in. I’ve suspected from the exhaust that the turbo may
be going downhill, and was wondering if these recent symptoms would
give any indication towards that conclusion. If this is the problem,
what kind of costs am I looking at for repair/replacement? Thanks,

Coles Jennings

 

The lack of acceleration and vibration probably aren't the turbo - or at
least it isn't the first place to look.

For the smoke, clean all the parts of the crankcase ventilation system. That
includes the air/oil separator box bolted to the block and the hoses that
connect it to the turbo intake hose. Replacement of the air/oil separator is
an easy alternative to cleaning it.

If the crankcase ventilation gets too restricted, the crankcase pressure
will rise and cause the turbo drain to back up and overflow oil into the
exhaust. (It happened to mine, and the smoke was impressive indeed!)

When clear, you should be able to blow through the hose and separator as
though it was about a 3/8 inch diameter hole. My separator had the
resistance of a soda straw.

Mike

 

First thing I'd do is check all the hoses under the hood. It's fairly common
for a rubber fitting in the intake tract to develop a hole which leaks boost
and affects engine performance. Also if it has the LH JetTronic fuel system
the air mass meter is a common failure. The acceleration should be very good
on that car, something is definitly wrong. Mine takes off like a bat out of
hell.

 

HOW ABOUT A GOOD CLEAN OUT of the fuel mixture thingo under the intake
manifold .It can be washed out rather than replaced .As well the trottle
body most likely needs a good clean .You might Take out the intercooler and
clean that up as well .Use synthetic oil I use BP Synthetic for get all the
claims from amsoil and their hard sell .My wife car has done 240+k amd mine
164kwe use synthetic oil and my sons has done 300+on dyno oil hasnt had its
first change since we got it yet .None of them leak or use oil .So your is a
baby just running in .Cheap oil is bad oil ,Synthetic oil is great for
Turbos no crudding up in the turbo bearings .My last cars did 443.000
880.000 and the other you wouldnt believe any way , but it was over a
million .I used to drive for a living now I am retired I like to spoil my
car .I am bored

http://www.autoforumz.com/eform.php?p=535596