2009 E350 Engine knock

[amg280]

Hello Guys. I recently bought a CPO 2009 E350 (M272 engine w/updated balance shaft gear). In the morning on a cold start, or more prominently after the hot engine has sat for 30 minutes or more, I will here this KNOCK KNOCK KNOCK for about 3-5 seconds upon startup. It definitely sounds like a lower end issue, NOT a valve train "tap". The car is under warranty and has been to the dealer TWICE for this issue only for them to tell me either "no problem found" or "its normal". Now, I HAVE heard and read about many other cars doing this with the same engine. I still don't think that makes it acceptable on a 50K plus car. My indy thinks it is bad crank bearings, causing the crank to move fore and aft, and always says when I leave (the car knocks so loud on startup he hears it from his office), you better get that fixed before your warranty runs out.

I bought it CPO with 34K on it. Currently it has 41K. I have done two oil changes, both with the recommended Mobil 1 Syn 0W-40. I cut the maintenance interval to 5000 instead of the MB recommended 10K. Maybe its a waste of money but that's neither here nor there.

I am concerned obviously for when the warranty is up and question the longevity of this engine. Clearly this is not normal. It is downright embarrassing trying to explain to passengers "Oh that's normal" on such a newer car with warranty. In typical Mercedes USA fashion, they will DENY DENY DENY (look at the balance shaft issue that covered ALOT of M272's).

Has anyone confirmed WHAT is actually causing it? My indy told me has a client who bought a brand new one for his wife and actually had MB buy it back because his was knocking all the time (not just at startup). Same year and model as mine. I recently heard a brand new CLS550 startup near me at the local Staples and his did the same thing (V8 engine). What is with these newer engines? Now I guess there is a TSB out for the new (2012+) 3.5 direct injected motors that effects the wrist pin bearings, etc, and require a rebuild!

What course of action do I have? Try a different dealer? Call MB (they don't care). Request regional field rep to be onsite? I feel MB is pushing me away until the warranty has run out to protect themselves from a new engine or rebuild. Mine is so loud when it does it, it makes my 300D Turbo (with 273K) sound like a brand new Lexus LS.

Any help would be greatly appreciated!

Thankyou.

[Zulfiqar]

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.

[ILUVMILS]

Originally Posted by Zulfiqar

..The procedure was very long but it entailed opening the engine up, reading the casting nos. then getting appropriate main bearing shells.

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.

[amg280]

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!

[junqueyardjim]

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!

[ILUVMILS]

Originally Posted by amg280

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?

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.

[amg280]

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!

[Zulfiqar]

Originally Posted by ILUVMILS

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.

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.

[amg280]

Originally Posted by Zulfiqar

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.

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.

[Zulfiqar]

- YES

that whoosh whoosh is the type of sound I hear, very soft deep sound but only at idle.

[oldsinner111]

they have a dumb bunch in Kingsport Tennesse,so If your on interstate 81 push,or pull it to Knoxville.

[amg280]

I 'managed' to get all the old parts back from the dealer that did the job this week, and needless to say, they are quite eye opening. I cant really say I agree with 'Mercedes' take that this is a "normal" noise, which is what they have brainwashed they're dealer network into telling the customers when they complain about the thumping noise on startups. 1 set of crank bearings (upper and lower set) are so scored, you cant run your finger nail across it without it getting stopped in the worn groove. I will let the pictures do the talking. I would like to hear what other member's opinion are on these. My engine had 42K on it when the dealer replaced them. It now has 43K and is still quiet (well, quieter). This engine was NOT beaten and had Mobil one 5W-40 (spec 229.5) oil changes every 6-7K. You be the judge.
If anyone wants any high res pics, PM me.

cheers

[oda112]

Do you have any idea how expensive such a job would be? I think I have the same issue on my m273 engine. There's a knocking sound at idle ( you can only hear it from outside the car though, if you get close to the engine bay) and the whole engine vibrates slightly ( I just replaced the engine and tranny mounts so the vibration isn't coming from there).
Also, how long do you think I can drive the car like this without major issues possibly occuring?

[compress ignite]

Were not the M272 and M273 Twins of Another Sort on the Cam Issues and
Class action suit ?

Any MB making "Lower End Noises" should be compared to the Band on the
Titanic Playing as She slipped 'Neath The Waves of the North Atlantic...

[oldtrucker]

How does the oil pressure gauge indicate at idle?

I would think that there is some major design flaw.
Either the oil delivery system can't built up oil pressure fast enough or the crank bearings are too lose.
That would be confirmed by at least one post.
At higher RPMS the oil pressure rises and all seems to be OK.

A simple test would be at next oil change to tell the guy's the heck with you I want SAE30 or something even thicker in it. The Higher viscosity would fill out the otherwise dry areas and the engine should not make the clonking noise.
Downside with higher viscosity oil, I see you maybe in New York, when it gets cold, the engine has to work harder to start up.
Just an idea, to nail it!
Afterwards, put the recommended oil back in or drive with the higher viscosity oil.
Don't know if they still sell "Prolong" I would be tempted to put that in. Lets face it, MB is not admitting to the screw up and ultimately you'll have to eat the repair cost.

NOTE:
The way dealerships work is simple. If the main office doesn't put out a recall / repair (fix), a problem doesn't exist at the dealerships. The dealer can't confirm, because the dealer would eat the cost of repair. It's that simple.
MB USA can't confirm either until MB Germany, with the OK of the Arabs of course, admits to a screw up!
Nobody wants to pay for the repair, so let the consumer pay for it, isn't that the way it always has been?

In return, Mercedes's image get's hosed. But who cares? They just don't sell as expensive anymore, the strategy is now, quantity, hurray, life is good.

Forgive me for saying this, but Hyundai and Kia (not quite at the same status) has become a better value than any of them high priced coaches.
If Mercedes keeps on going that way, (hate to say it, I am German) it will become just another Toyota.