PeachParts Mercedes-Benz Forum - View Single Post - It's back!!! (and I already have a new question ...)

BodhiBenz1987 · #1 04-10-2010, 04:34 PM

So after a winter of straining, worrying, getting buried in snow and at one point just plain giving up, I finally got my 87 300D back on the road today. Basically all I did was the front brakes, wheel bearings, flex discs/center bearing and all new exhaust hangers, but somehow managed to turn it into an epic adventure (that outside circumstances made worse). But it's back and running/driving great ... no vibrations from the driveshaft at all (even through my very paranoid ear), and to boot, the little leaks that had me worried during the winter have stopped (probably because it isn't 7 degrees out anymore ... although I'll address them anyway to stay ahead of the game).
Of course ... I do have one issue. From inside the car, only at idle, there is a very low, very annoying vibration/humming noise. You can't hear anything outside or even under the car, really. Inside it's very noticeable, almost subsonic. Exhaust leak is my guess. Does that sound plausible? I did have the exhaust dropped down to get to the driveshaft, so maybe I disrupted a trouble area that was already forming. The new hangers work great and I don't have the rattling I had before. But it's going to make my head explode with the subtle humming. It vanishes at throttle (After driving the 240D for a while this car is eerily quiet.

). In idle it makes the humming in any gear. Driveshaft wouldn't make sense, right? That would be the opposite effect (noise/vibr. at throttle, none at idle). Input, please?

It's not unlivable or cause for panic. But it's going to get annoying ...

Exhaust issue or not, I love having this car back ... I can't believe how fast, smooth and comfortable it is.