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’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

Reply to
hcj2k
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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

Reply to
Michael Pardee

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.

Reply to
James Sweet

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
Reply to
John Robertosn

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