Turbo Noise ? - PeachParts Mercedes-Benz Forum

Tpawlik · #1 10-11-2010, 09:45 AM

I was having a loud vibration noise in the rear end which I fixed. Now that the rear end is quiet, I still have this roaring sound at any RPM above 2,000 at 70 mph/2,700 rpm, it is really annoying. Below 2,000 rpm the car is as quiet as a gasser. I made a 200 mile round trip on the Interstate yesterday and my ears were ringing when I got out of the car. It gets noticeably quieter when I go down an incline. Just taking some load of the engine makes a big difference. I have checked the front turbo wheel and it has no play in it and it turns freely. The turbo does not whine. I cannot hear the normal mechanical sounds of the engine over what I believe is the turbo. The PO had the trap oxidizer removed and a new exhaust system installed by the dealer within the last 6 months. I used to own a 300SD, it never made this much noise at 70 MPH. Something is not right.

vstech · #2 10-11-2010, 09:55 AM

within the last 6 months? take it to the dealer it was done at, and see if the turbo needs to be replaced! it's part of the recall, and should be done for free.

Tpawlik · #3 10-11-2010, 10:44 AM

That's going to be difficult. The dealer who removed the TO is in Delray Beach, FLA.
I could call one of the two dealers in Cleveland and see what if anything they will do for free. What happens to the make the turbo so loud?
I don't know why I could not place where Mt. Holly is, I lived in Tega Cay on Lake Wylie and used to go to Gastonia now and then.

vstech · #4 10-11-2010, 10:45 AM

between charlotte, and gashouse, just a tad north. the trap-OX was known to fail, and debris from it would destroy the bearings and the blades of the turbo. complain, show your recipt for the ox change, and pray they do it for you!

Tpawlik · #5 10-12-2010, 12:09 PM

I can't stand the noise any longer, I am taking the car this afternoon to George Gantner. He is listed in the Good MB Shops, Cleveland, OH area.
I will let everyone know what he thinks.

Tpawlik · #6 11-03-2010, 07:11 PM

I'm still stymied. I had the left rear wheel bearing replaced. Needed it, but it was not contributing to the noise I still have. Replaced both front wheel bearings and races. Changed rear diff fluid to Red Line 85W 140 synthetic oil. Quieter but still not the problem. Any time the engine is under 2000 rpm the engine, tires, rear end all sound good, really quiet. The second the turbo starts to add power, the noise is awful. When I let off the throttle and the turbo slows down, the roaring stops and I can actually hear the engine, which sounds good.
I found a leak in the inlet plumbing and fixed it. I thought I had solved the problem, because for some reason it is much quieter for the first 10 miles or so when cold, then anything over 2,000 rpm is really obnoxious. When I had the rubber elbow off the front of the turbo I spun the turbine and tried to move it side to side and in and out. It turned easily/smoothly and had no play.
What further checks on the turbo can I do myself?