Engine whistling after start
 

The air cleaner assembly in my '83 300SD was shaking a lot ever since I bought it a couple years ago. I finally got around to adjusting it and it doesn't shake anymore. Now I'm getting this whistle that pitches up and down along with the engine RPMs. the whistle lasts for about a minute after the engine starts, disregarding engine temperature, and then stops, not to be heard until next tiem the engine starts. When I was doing this I remember disconnecting the little rubber line that goes to the turbo just below the filter assembly towards the front, but I reattached it and doesn't look like it's leaking or anything. Any ideas?

The wastegate hose could be cracked but not obviously visible on inspection. Pressure inside could cause the whistling sound.

Also, the U tube connecting the air cleaner to the turbo inlet has two large seals, if these are not installed properly they could leak in air and can cause the whistling.

When the Engine is cold if you spray the suspected areas down with a mix of Dish Soap and Water; if there is any sort of pressurized Air Leak it will bubble.

Thanks guys, I'll check those hoses and tubes for leaks... I like the soapy water idea too :)