What does your turbo sound like when it spools?

[otto huber]

I ask this question because I'm trying to figure out whether my turbo is working properly. I'm under the impression that it only works intermittently.

Lately, the 300SD has been a real dog on hills. This evening as I was driving up a steep highway entrance ramp, I floored it and got this glorious roar and the car took off. I was like, "wow where'd that come from?" . I've had a few of those moments since I bought the car 5 months ago. My previous car was a 240D, so I really had no idea what a powerful diesel engine feels like. I've read posts where guys describe a whining sound from the turbo, but I'm getting more of a low roaring sound.

I've already done a search and will check for play in the spool, and check the over boost solenoid. I've already cleaned the banjo bolt, it looked pretty good. There was also mention of turbo ring seals failing and oil getting into the intake manifold. I noticed a lot of oil seems to be dripping from below the intake manifold. I recently changed the valve cover gasket, so I don't think that the oil is coming from the valve cover.

Will a properly working turbo improve my mileage? I'm currently averaging 22 MPG's city/hwy. thanks