Mechanics

UNDERNEATH NOISES

1997 BMW 540i

Noises problem
1997 BMW 540i V8 Two Wheel Drive Automatic 165000 miles

When running at steady speed car sounds like its changing gears up and down constantly but looking at the RPM's staying steady its not changing gears. Transmission works fine and changes as it should.

Also rough roaring noise when cruising speed is steady and car not pulling but maintaining speed. Stops when gas is increased. Doesn't do it ever above 80 MPH.

May be two separate things.
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Alabama John
July 17, 2010.



Sounds like the transmission is pendulum shifting, it could be software.

Dr. Hagerty
Jul 18, 2010.
Dr. Hagerty,

Thank you for your answer.

If it is pendulum shifting, can the software be reset or what to do about the software?

Could it be the fan sensor or even the catalytic converters since I have 100,000 miles on them?
They are something aftermarket so my check engine light stays on.

Tiny
Alabama John
Jul 18, 2010.