Mechanics

RPM DROP, CHECK ENGINE LIGHT

1995 BMW 540i

Engine Performance problem
1995 BMW 540i V8 Two Wheel Drive Automatic 209000 miles

Engine rpm drops abnormally quickly. Check engine light illuminates if rpm not maintained above 1,800rpm. Trouble codes for Lambda 1 and 2, O2 sensors 1 and 2, mass air flow sensor - all present as
retrieved by bavarian autosport scan/reset tool. If codes are reset - car acts normal until rpms are allowed to drop below 1800 rpm for more than 10 seconds. Then car runs very roughly until reset with tool - and cycle repeats. Worse in cold weather.
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540iWILL
January 10, 2010.



Has the PCV plate been replaced? Are the intake gaskets all original?

Dr. Hagerty
Jan 11, 2010.


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