Transmission rattle in neutral. Mechanic says normal.

[Neil Deshpande <deshpand@xxxxxxxxxxxxxxxxxxxxxxxxx>]

My 1988 325is makes a rattling sound from the transmission when it is in
neutral.  It is clearly audible at idle at 600 RPM.  Any higher and it
either goes away or is drowned out by the engine noise. 

One mechanic I took it to says it is normal backlash noise.  This sounds
reasonable to me. 

It never did this before, but I have cured a high idle problem only
recently by cleaning out the idle control valve and put in Redline MTL. 
The MTL, being thinner(?), might not damp out the rattle as well.  Any
opinions? 

The rattle occurs only when the car is in neutral.  If I disengage the
clutch (push it down) the sounds goes away completely.  Of course, it
might be happening when the car is in some other gear, but it is not as
easy to hear when the car is moving.

Neil Deshpande 
88 325 is 
89 325 iC

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