The lower end rumble on startup has been reported by a few posters. I read of one who had his engine repaired by MB, The procedure was very long but it entailed opening the engine up, reading the casting nos. then getting appropriate main bearing shells.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Bingo! Once the engine is apart they can see which bearings were fitted from the factory. They'll install bearings one size smaller to tighten things up a bit. My shop has done a few of them over the last few years, with good results.

FWIW, having your car make this DUNK-DUNK-DUNK.......noise on start-up can be a bit embarrassing. It'll definitely turn a few heads in the parking lot! Let us know how you make out.

Thanks for the responses guys.

ILUVMILS: When your dealer has done these repairs, what bearing are they actually replacing? The center thrust bearing for the crank shaft? All the crank bearings? Any of the piston bearings? What did the customers have to do at your service center to basically have Mercedes warranty this defect? Does the dealer measure the fore/aft play on the crank before pulling the engine? Do you know the spec?

I feel every time I start it up in the morning, I'm doing damage, that I know will eventually just keep exasperating itself to the point where it might let go in the future. The car knocks louder after it sits hot for 30+ minutes than it does in the morning. Its a shame, I absolutely love this car, everything about it. It sux that I have little piece of mind about the motor. I'm going to call the dealer today to yet complain AGAIN. Frustrating.

Thanks so much for taking the time to respond to my questions. It is MUCH appreciated.

Andy

One thing I forgot to ask, if nothing is done, what is your opinion on the longevity of the motor? Will it progress do you think? Stay the same? Thanks!

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93 300D 2.5 Turbo, Black/Palomino 273K
09 E350 Black/Black 41K

You could start by giving the BBB a call. That is what they are there for and believe me, the dealer doesn't want to hear from them. However, they might still try sleeping through. Then I would start with having an attorney give them a wake up call. You will get there attention. Let them know you mean business!

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

The main bearings are the cause of the noise. Yes, the thrust bearing is replaced. No, we don't measure fore/aft crank play prior to dis-assembly. We replace the rod bearings as well, but only because we're already there, so why not?

The customers didn't have to do anything other than bring the car in and complain about the noise! Obviously something is wrong, right?

When we had the first few complaints MB didn't have a fix yet, but was aware of the problem. We recorded the DUNK-DUNK-DUNK noise on a few different cars and sent the sound files to MB Technical Assistance. We asked our clients to be patient, and within a few weeks MB Service Engineering had the solution (Yeah, I'd like to tell you that we figured it out at the dealership but I'd be lying if I did. We knew it was a bottom-end issue, but if we took a crack at it without MB support we would've just replaced the bearings with the same size and the noise would still be there).

Once we had the answer it was simply a matter of contacting the owners of the problem cars (yes, we keep track of stuff like that) and scheduling appointments to make the repairs.

Once the engine(s) were torn-down we simply recorded the casting numbers on the block and crank, ordered the appropriate bearing shells, and re-assembled everything. Problem fixed. It's not like building an engine from scratch. No micrometers, plasti-gage, etc. required. No specs to look up. No clearances to measure. The casting numbers have all the information needed to do the job right.

My shop hasn't done this job in quite a while. I figure that most of the problem engines have been fixed already. Maybe your dealer has a short memory? If you're dealer can't/won't acknowledge the problem, the first step is to call MBUSA Customer Assistance. Let us know how it goes.

Thanks for all the help and the explanation. That is precisely what my Indy said, crankshaft bearings. Too much slop so it moves for and aft until oil pressure builds.

The car is going to the dealer for the 3rd time for this issue next Thursday. This time, I'm going to be there when they start it up 1.5 hours after I drop it off....

Will let you know what happens.

For the sake of argument, say I had no warranty and was going to do this job myself, say over the winter. What would I tell the parts department to get the proper bearings I need? Give them my casting numbers and say "do math". Reference a TSB? Which bearings exactly have to be 1 size smaller? The top crank?

thanks again!

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93 300D 2.5 Turbo, Black/Palomino 273K
09 E350 Black/Black 41K

Hello. Just to update this scenario:

The car is at the dealer. One of the mechanics, the SA, my friend, and I all witnessed the noise at the dealership "check in" bay when I started the car up two hours after I dropped it off this morning. The mechanic at first said the noise was somewhat normal (hesitant). He then said it sounded more like a timing chain issue. I hinted at the fact that my research indicated it could be crank bearings, and MB is aware of this issue on the M272 motor.

It wasn't until I showed him an invoice of an anonymous person on the internet that had this same issue fixed that he said "I guess it could be that, but we have never done one".

Long story short, it went from being "normal" to "a problem", to getting shop foreman/MB involved. They wanted to keep the car there for 2+ days for investigating so I left it with them today. Will see what they come back with. I hope good news. I really want to get this motor repaired as I plan on keeping this car till the wheels fall off, and quite honestly, its embarrassing trying to explain a loud, consistent (sitting for 30+ minutes hot) engine knock to friends and family. I truly believe this will effect the longevity of it (I hope im wrong).

I will let you know what they come back with.

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93 300D 2.5 Turbo, Black/Palomino 273K
09 E350 Black/Black 41K

Well I called my SA after them having my car for 3 days. SA stated they ARE going to go ahead and replace the crank bearings. Unfortunately they could not give me a time frame. Hopefully within 2 weeks. For those of you who are experiencing this, I highly recommend you press the issue and use the resources of this forum to get it fixed. I will report back when I get the car back, and hope all is well.

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93 300D 2.5 Turbo, Black/Palomino 273K
09 E350 Black/Black 41K

My M112 makes a noise on startup that I can only describe as chain/lifter noise, It was very loud when I bought it, on the first oil change I discovered a paper filter which was about 2 inches short of hitting the cap top hence 2 inches of the central tube was visible and hence unfiltered oil was passing.

After the oil change with new fleece filter and Delo 400LE and after 6500 miles driving it has quietened down a lot, but I do hear a deep soft thumping from the engine at idle - dealer and indy both have no answer to that. The engine pulls hard and sounds fantastic at speed after new spark plugs (old ones were factory items at 157,000 miles)

I leave it be as the nature of the car, same with the new 3.5 engines toyota are using in the camrys, siennas, ES350 etc. They are like a silverware drawer on startup.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I also had an M112 (2001 E320) that I had since gotten rid of. That was a good car mechanically, just the body didn't hold up to the NY winters. That engine ran strong, consumed a lot of oil, but was generally quiet. The only noises that engine made were timing chain noises (whoosh.......whoosh......). Apparently that was quite common on those. But it had no valve tappet noises (sometimes early morning starts for a few seconds), and definitely no lower end rumble. My buddy still has his 2000 E320 4M with 200K on it and that engine, other than the TC noises, sounds great. I agree, all the new direct injected engines are noisier than what we are (were) currently used to.

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93 300D 2.5 Turbo, Black/Palomino 273K
09 E350 Black/Black 41K