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Jim2 Jim2 is offline
7.0:1 > 11.3:1
 
Join Date: Oct 2003
Location: Calgary
Posts: 1,821
Garage
Spruce, if you developed a rather sudden scavenge problem it may be similar to a problem I encountered. My 930 developed tailpipe oil smoke at idle. I found that my turbo bearings had worn to the point that the oil flow rate through the turbo exceeded the scavenge pump draw rate while at idle. Since the scavenge pump volume is proportionate to engine rpm the scavenge pump could keep up if if the engine was reved a little, but it was not able to keep up at idle.

Upon disassembly of the turbo my ring seals were fine, but the turbine side bearing had failed.

The bearing deterioration became gradually noticable over a two hour period, though the car was being tracked at the time.

I replaced the turbo bearing housing and bearings and my problems were resolved.
Old 06-17-2007, 08:22 AM
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