Turbo Whine
 

84 300D. Just did the valve adjustment, everything runs fine, shifts fine, no power loss, no leaks noticeable. Except I can hear the Turbo spooling up and down from the cab. Whining like my old Cummins. Turbo to air cleaner connections verified tight, no loose hoses that i can see. When I go under the hood and spool it up, the whine is coming directly from the intake scoop opening, forward of the air cleaner housing. Never heard it before that I remember.... Any ideas?

Is the whine coming from the air intake at the front of the car or where the air cleaner assembly connects to the turbo housing. The rubber seals in the air cleaner to turbo connection (there are two of them) are common wear items due to the heat they're exposed to. I had the same issue - my 300SD started to sounds like it had a small jet engine spooling up in the engine compartment - and it turned out to be a loose rubber seal.

You can buy the parts from Phil here on this site or there is a fine pictorial on how to replace them on the dieselgiant web site.

Nope, its coming from the actual intake scoop at the front of the engine. Where air is drawn into the air cleaner assembly. If I put my ear to the opening scoop, I can hear the whine coming from down inside the assembly. Its definitely not coming from the turbo connections.

You should be able to hear just a wee bit of a whine on a stock setup.

This is really noticeable. More than I remember. Not like the turbo is coming apart, but just loud like a supercharger.

It may be time to check compressor shaft lateral runout. Do you think the compressor fins may be contacting the cold side of the housing?

If it's a Cali Model, then try unplugging the ARV vacuum line and plug up that line. The ARV could be sticking and causing the whine.



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