Buzz and Vibration in 240D
 

Everyone, this is a fantastic site! I found it a few weeks ago and have been reading it almost nightly. My wife says I'm in love. I couldn't stand just reading all the advise from some obviously very experienced MB owners, so I had to join and ask for some of your wisdom.

I previously owned a 1976 240D 4 speed with I don't know how many bazillion miles on it for about five years. What a great car. I finally donated it to charity and last March purchased a 1983 240D 4 speed with 133,000 miles on it for $2200. This one has working A/C I am thrilled with. It must have been owned by a gizmo freak since it has a TurboZet (I think it is worthless as a power boost) and an electric clutch that when turned on with your thumb (small toggle on the shift knob) you push another button on the shift knob with your thumb, it pushes the clutch in and out for you (acts like a semi-automatic) as you operate it in bumper to bumper traffic, (I don't use it, too much trouble to figure out!).

Since purchase 3 months ago I have had:

The timing chain replaced, Valves adjusted, Compression tested (400, 400, 400, 380), transmission shift bushing replaced, replaced front engine T-mount, replaced transmission tail shaft mount, replaced steering shock, and various hoses, all by a independent mercedes mechanic.

Sorry for the history, now to the problems.

1. There is a buzz connected to the clutch, driveline, ?? that is probably always there but very LOUD after 60 mph. It will stop and start almost instantly. It has my mechanic baffled after two visits to him, he says I need to remove/replace the clutch now. I tested the theory tonight and at 70 mph when the buzz is on I tap the clutch. About half the time the buzz would instantly stop for a few seconds, then start again. Resting my foot on the clutch while buzzing, the pedal seems to vibrate more than when buzz is off. Motor and transmission mounts I am told are fine. Any ideas on what this is and how to solve it? How much should a new clutch cost?

2. There is a whole lot of black/dark grey smoke at idle and take-off or when pressing hard on the accelorator at speed. Doesn't smell like burning oil when I look at it in the parking lot. Not noticable at cruising speed. I am in the process of gauging how much oil I am using. I am definately using more than 1 qt per 700 miles. May be using more, survey is still in process! Don't appear to have any noticable oil leaks. Mechanic says it needs valve guides (valve job). He said it wasn't injector pump or injector timing or vacuum related. The air cleaner is clean, no oil there. Mechacic said to hold off on the valve job for a long while and just keep adding oil to it and forget about the people behind me beathing the smoke. I don't want to spend money if I don't have to, but I am a little embarassed by all the smoke and feel alittle bad for those people behind me, especially in stop and go traffic in CA bay area (I'm sure they are reporting me to the smog watchdogs!) Any ideas?? If a valve job is needed, what is the cost? What other repairs should be done at the same time when the head is off?

The car starts and runs fine, with similar acceleration as my 76, although it does chug more than the 76 (that thing was a smooth machine for a diesel). I get 27-28 mpg all the time. I love these cars but I'm beginning to wonder about this one, bought it for 2200 and in three months put another 1600 in it. If I fix the clutch and valve job what else will be going wrong about now! At 137,000 I thought the car was almost new!!

Sorry for the long post and thanks for your help.

Tim