95 M3 Engine noise

[Porsche1VW@xxxxxxx]

I rercently purchased a 1995 M3.  When the engine is cold, after setting for 
about 3 or 4 hours, it is noisy at about 3000 to 4000 RPM.  It sounds a 
little like a diesel engine or some sort of valve train noise.  As soon as 
the engine warms up the noise goes away and everything seems fine.  I am 
using Casterol Syntec full synthetc oil 5W-50.

I have been told that this is not unusual for the M3 and that it is related 
to either the VANOS system or the timing chain tensioner, and not to worry.  
I do worry however, and would like to remedy the problem and eliminate the 
noise.   Can anyone help or comment on this.

Thanks.

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