Hello, my 83 MB 300SD diesel started making a grinding noise but only when I accelerate. As soon as I ease off the gas pedal the noise stops. Otherwise, the car runs fine. There doesn't seem to be a slowdown in performance either. The engine has 342000 miles. Any idea what that clattering noise can be and how I can fix it?

thanks

That's probably your axles. Check them out. Crawl under the car and see if the rubber boots are torn in the rear axles near the differential and the wheels. 4 boots total. If they're ripped they leak out the oil and the axle gets worn out shortly after.

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-190d '89 Non Turbo 2.5 5cyl 240k (my first MB)
Tom's Imports of Columbia MO Ruined the IP in changing leaky delivery valve O-Rings - Refused to stand behind his work. Mid-MO MB drivers-AVOID Tom's.

Front end or back end noise?

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

front end noise, thanks

I too have that noise only when turning left, i am thinking its the wheel bearing are worned...

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1995 E320 SE 220k mi
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No, the noise happens when I accelerate only. It doesn't matter if I turn left/right or go straight.

Could be a belt driven accessory device with a bad bearing or even the air cleaner rattling.

Use a stethoscope or long screwdriver against your ear and listen to various parts of the engine compartment whlie a friend operates the throttle.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Also... try a few revs at idle and see if it still happens. Get it in the 3k or so range and see what you hear. My air cleaner housing rattled like crazy when I had a w123. I had to rig a way to keep it down. Probably could have ordered grommets but it never lined up right.

Make sure it's from the front. Sometimes it's hard to centralize a sound. I'd check your Axle boots anyways if you haven't. Even if yours aren't making a sound, I'd bet their shot if they're original. I've yet to see a 123 or 116 etc that has good original boots. Those crack and leak and you'll be replacing the axles which is much more expensive than a boot.

__________________
-E300d '99 350k
-Suburban '93 220k
-TDI Jetta '03 350k
Sold
-F250 '96 7.3
-Dodge Ram 12V
-E320 '95 200k
-E320 Wagon 1994 155k
-300d Turbo '87 187k miles
-E320 1994 200k
-300d Turbo '84 245k (sold to Dan62)
-300d Turbo '84 180k
-300sd '80 300k
-7.3 Powerstroke Diesel 15P Van 500k+ miles
-190d '89 Non Turbo 2.5 5cyl 240k (my first MB)
Tom's Imports of Columbia MO Ruined the IP in changing leaky delivery valve O-Rings - Refused to stand behind his work. Mid-MO MB drivers-AVOID Tom's.

Thanks, I just checked for the grinding noise running the car in idle. Sure enough the noise is there, so, I guess probably my air cleaner housing is loose or busted. It's not the first time this sucker was rattling bad. In my opinion one design flaw in an otherwise perfect machine. I'll check the axle boots as well to be on the safe side.

thanks

One more thing: there also seems to come a "tacking" noise from the front bottom of the engine, near (or from) the belt assembly. It too gets louder when I run about 3000 rpm in idle. Any idea would could get loose down there? I know that's vague but maybe someone has experienced something like this before(??).

thanks again.

You should be able to push or pull on the air cleaner while it is making the noise to determine if it is the culprit.

Dropping the tension or removing your belts and running a "COLD" engine for 30 secs MAX will tell you if the noise is an accessory device or engine related. If nosie disappears, spin each device by hand and feel/listen to bearings.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Hey thanks everyone. Found the problems: 1. the air cleaner housing is loose, rubber stops are broken in half. 2. the fan blades hit the flywheel. So... that takes care of that. Those air cleaning housings in 83 300SDs are surely not too well designed as far as "staying put" is concerned.

Any how, thanks again for all the good advice.