On the way home from work tonight is payed very close attention to what happens. I think I know what the source of noise is....probably cold weather turbo noises. When I start the car, first start on cold morning or at night after work, the noise does not appear when in neutral (I'm assuming the turbo does not engage when in neutral???). But when I put it in drive, the noise is very pronounced. The noise appears at about 2,500 -3,000 rpms or higher. (is this about when turbo engages??) When I let off the accelerator, the engine quickly revs down to about 850 rpm (normal idle speed) but I still hear a very very pronounced rough gear-like noise...or a noisy spinning shaft....at high rpms noisily slowing down....seems that this is most likely from the turbo....i.e.the turbo rotor/shaft spinning and slowing down (???).


Once car is fully warmed up, noise goes away. In warm weather, no noise, car runs fine, turbo seems ok.

Is this cold weather turbo noise a symptom of a failing turbo. The car alway had regular oil changes, synthetic oil fo rthe last 175,000 miles. but the car does have over 300K on it, and the turbo is original.

Anyone have an opinion here? Am I now, or will I soon be in need of a new turbo??? What could explain this....do turbos in general hate very cold sub zero air??

Thanks

Mark

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1984 300TD Wagon, 407,800 mi (current daily driver)
1985 300DT Sedan, 330,000 mi (gone to that great autobahn in the sky)