I have been reading the archives regarding turbo "whine" as my 1985 300D has similar problems.

The turbo was rebuilt by Majestic Turbo in Texas. Since re-installation, I have noticed a "whine" as the turbo spools up, then quiets down somewhat at highway speeds, although noticable.

It does not sound like a whistle or air leak. The sound is more like a turbine engine spooling up, almost like a siren. The archives suggest there is a possibility of the flex pipe behind the turbo being the problem.


I did not drop the exhaust assembly when I removed the turbo, rather I removed the three flange bolts, moved downpipe around enough to remove the flexpipe, then removed the turbo. Also, I did not remove the intake or exhaust manifold. When re-installing the flex pipe, I noticed it was just a little off angle between the turbo and downpipe. I would think if anything, there would be an loud exhaust leak, unless the sleeve inside the flex pipe is lined up properly and the turbo is "leaking air" around the flex pipe. Any thoughts? Alan

Check the air filter and turbo intake pipe. Turbine noise on a Benz is often a loose air intake pipe, they are normally very quiet. If the exhaust was leaking enough to give you a whine, it would also roar.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks for the tip, I assume you mean the "U" shaped plastic pipe that connects the air cleaner assembly to the turbo inlet. There is a rubber gasket at each end, can be very difficult to re-attach this pipe without pinching the gaskets. The air filter inlet fits tight. Alan

I love to hear the "whine" of my turbo as it spools.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012