This is from my '85 300CD-T.

I started getting a bad (read: loud) engine vibration about 2 months ago. Loud kind of vibration (can hear *and* see it) that occurs between about 1,400 RPMs and 1,600 RPMs. Builds-up starting at about 1,400 and goes away after 1,600.

Have tried hard to isolate the source. Appears that it might be coming from under the valve cover (right side of engine). It happens whether driving or revving with the transmission in Park/Neutral.

Worried about engine damage if I drive the car.

Any ideas?

Air filter mounts? motor Mounts?

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

I went out and ran the engine and checked both. I don't think so.

I estimate that the sound is coming from the area between the oil cap on the valve cover and the turbo charger. Right in that about 6"-8" square region.

Do a valve adjustment.

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83 SD

84 CD

Yeah, just what I've been thinking. At least take off the valve cover (a little hot at the moment), and see (dare I look?!) if there's anything obviously not right. Yikes.

Deep breath - if it was really bad you'd hear it!

Don't forget to get yourself a new rocker cover gasket otherwise you'll be asking about oil leaks next week.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Got it.
My schedule is such that I'll do this three days from now (Saturday).

Thanks for all the posts.

While you are looking at the valves, take a good look at the chain while cranking it over by hand. look for any loose or broken links. there was a chain posted a while back, the side link fell off and the other side was working it`s way out.

there should be a DIY article on checking the timing chain stretch.

Here it is:
http://www.peachparts.com/Wikka/OM617TimingChainStretch


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Thanks, I'll take a close look at the chain while cranking as I do the valve adjustment.

Hi
It might be worthwhile when you have the valve cover off to spin the engine with a remote starter switch and observe the valve action.
Joseph

Cracked air filter bracket? The rubber mounts might be okay, but the part they're connected to...?

If you decide to do that or use a remote switch to bump over the engine while doing the valve adjustment, make sure you have the stop linkage pushed towards the Valve cover or the engine WILL start.

then you will get excited as oil is squirting out and running down the sides of the engine.

I have first hand experience that it can happen.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The car is a Calif. model so it has the unusual air filter canister that goes with the I'll-fated trap oxidizer. I'll pull the canister and look underneath at the mounts. I've done a head replacement on my other 300CD, however, never gutsy enough to crank the engine w/the key while having the valve cover off. Either the unadventurous type here or mechanically conservative...

Guy at BAP forgot to order the new gasket after I paid for it so set to pick it up tomorrow night and do this on Saturday.

Thanks-

See if you can turn off the engine with the manual shut off under the hood..
if you can.. you should be able to wire that lever in the closed position and be safe to turn it over with the key without it starting...

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Removed the air filter housing, checked the mount, everything was completely secure there

Removed the valve cover, checked clearances for all of the valves, only one was in need of adjustment. Incidentally, the last valve adjustment was a mere 450 miles ago (Oct, 2010). Also turned the engine over (while preventing it from starting) and did not notice anything unusual with any of the ten valves. Completely turned the timing chain and found no missing or damaged links or anything else that looked abnormal. Timing chain replaced 50,000 mi. ago (Oct, 2001).

Spent a lot of time cleaning and looking around the right side of the engine (where the noise seems to be coming from) and found two missing bolts for securing brackets in the area of the starter. Replaced the bolts.

I continue to think that the vibration is originating from around where the turbo charger connects to the intake manifold. As I ran the engine, I stood (I'm only about 135 lbs.) on the manifold/turbo charger and the noise/vibration did noticeably decrease by doing so.

Many, many years ago, I acquired a kit from a M-B dealer that was comprised of a few light blue rubber seals that were for where the turbo charger (of my 1983 300CD-T) connects to the engine. Is it possible that there are such seals that go with the turbo charger on this car that could be worn or missing and are thus causing a metal-on-metal vibration? Does anyone know anything about this?