2009 E350 Engine knock
 

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.

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.

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!

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.

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!

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.

- YES

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

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!

update:
 

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.

update
 

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.

CAR FIXED!
 

Hi Guys...

I got the car back about a week ago. The problem is fixed! No more knocking at any startups. They replaced all the crankshaft bearings and timing chain tensioner (one time use). Everything seems fine (been driving it for a week now). I will report back if anything goes weird, but it seems rock solid. I did notice a MB tech doc on my SA's desk outlining this procedure. Its a problem MB definitely knows about and has put together a packet for dealers on how to fix it! My particular dealer had the car about 2 weeks.

Good luck to any others pursuing this fix. It, like others have said, should be fixed without having to jump through hoops with your dealer like I did.

Regards

Congrats! I'm sure the dealer lost their ass on the job, but at least they realized that it's important to have satisfied customers. Enjoy your car. :)

Thank you. It was an uphill battle from the beginning. This was my 4th time complaining about it. Their lack of communication is appalling, as is their service dept.

When I picked up the car. I was halfway down the road before I realized I was robbed. Yes, robbed. My iPod in the glove box was gone, as well as all my change in the ashtray compartment. My other random things (behind the cup holders) were strewn about the actual cup holders. We are still fighting with them about this. A very classy thing to happen at an "upscale" dealer. Especially since it was "inside" the facility the whole time and according to the GM, they have no surveillance cameras.

To add insult to injury, when I got home, I checked the oil level, and it was two qts low. Again, thanks MB. I added the 2 qts and am just praying this is it with this car. I have no fight left in me with this dealer for any type of warranty (or even non warranty) repairs. I plan to drive the extra 20 miles or so to a different one next time that I have heard good things about. AND they offer loaner cars even if you did not buy the vehicle at their facility.:)

I understand MB cannot police every dealership, but this dealer has just gotten out of hand in the way they treat their customer base, your car (looks like they washed it with steel wool), workmanship (letting a car leave without proper oil level), theft, etc. Its a great car marred by a shoddy support system, in my case at least.

Btw, thanks for all your help! This job probably wouldn't have happened if it wasn't for people like you contributing in this great forum :)

Regards...

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

Pic's
 

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

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.

272 Engine
 

That 272 Engine is a real piece of work between this bearing problem and the balance shaft sprocket on the 2006 units! wow I have 80,000 now on my 2006 so I'm just waiting for the balance shaft to go bad:eek:

Not!

Well, then I must be wrong and all the complaints about the dealerships are unfounded, since they happily fix every design flaw at their expense.
Actually, ILUVMILS said it himself. Only after the main office acknowledged and published a fix, it was repaired (although we don't know if it was completely free of charge). If main office wouldn't have done that, the noise would still be there.

Just an example, out of over 1000 reported bad wiring harnesses on the M104, there is just one case I know of that had been repaired at the dealers expense. Not even repaired, but the cost of the part was paid for by the dealer.
The rest of them were paid for by the customer / owner! And who knows how many bad harnesses are still out there.

Lets face it, nobody is starting a business just to exchange money or even give some away. But, if a flaw in design is detected, the least one could expect is an admittance.
The whole setup is so complex that nobody can be blamed for anything.
There is an exception of course. "Warranty" every new car owner hopes that something break's during that period.

The "main office" didn't acknowledge anything, they figured out how to fix it. Once the repair was verified the dealers were sent work instructions from the factory. Please re-read my post. :)

The reason it can take some time to sort out issues like this is simple. MB can't drop everything when one guy complains of an engine knock. Once they've received enough complaints though, they'll dedicate the necessary resources and do what's necessary to solve the problem. The one thing that most PP members won't be thrilled about is that they normally won't re-visit issues like these after the factory warranty has expired. They've been doing it this way for many years, longer than I've been aboard. Same goes for voluntary recall and service campaigns.

ILUVMILS,
I for my part will close the subject of customer service for a high end priced Mercedes motor vehicle.
Perhaps, there was only one person that complaint about his engine, at your shop.
I admit, that sometimes something goes wrong in a production run and someone installs the wrong bearings, but this is rare in my experience.

Using the Internet as a research tool, reveals that there are many complaints about this issue. Unfortunately, they are not in tabular / statistical form, they are spread all over the internet!
The unresolved complaints I found, aren't limited to just the M272 but also in regards to other Mercedes models.

Although, it is nice to see that a shop, actually volunteered to repair a possible design flaw, but if your shop needed the main office to have a fix submitted, I just don't know about Automotive repair anymore.

To m.akasha,
if the oil pan can be removed without the removal of the engine (probably not, depends on the oil pump and cross members), sorry I never had a chance to look at this model, you may be able to exchange the shells from undeneath the vehicle. However, since you probably have to remove the crank shaft to gain access to the upper shells (bearings) there maybe a number of covers, timing chain (if there is one) seals and other supporting components, to be removed. This is much easier to do if the enngine is removed. Also, it is better during the re-assembly to have a clear look at the components to perform a clean repair. e.g. placement of seals, bearings seated correctly etc.

Yes the engine MUST be removed
No machine work is required
Hope this helps

FWIW, we had several dozen complaints about the M272 engine knock. all were resolved.

I can see why you would doubt the ability of a shop that requires technical assistance from the manufacturer but you can't see the entire room by looking thru the keyhole. Here's how it works in the real world. No dealership would attempt a repair of that magnitude and expense without seeking advice from MB. We knew it was a bottom-end knock, that was easy to figure out. The question is what to do about it. Maybe there's a crankshaft issue we're not aware of. Maybe an oil pressure glitch that won't show up on the gauge (yeah, we checked that first)It would be irresponsible of us to tear down a motor just to "have a look". Why didn't we just replace all the bottom-end bearings you're probably wondering? Without the critical piece of information about using bearings one size tighter we would have done a hell of a lot of work for nothing. Why didn't we try tighter bearings and see what happened? What if the motor blew up? Guess who's paying for that? Not MB I can promise you! So we gather as much information as possible and pass it on to MB technical. Let the engineers figure it out. That's right, the engineers. I'm not an engineer and I don't have an engineer in-house. If they say install tighter bearings and the motor blows up then it's their problem, not mine. Sorry, but I have to protect the company I work for as well as satisfy my clients. I hope this clears up any confusion :)

Although, I was going to close this issue, I would like to say, I don't blame you or any other dealer for those things to happen. It's been a few years, about 45 since I was working commercially on motor vehicles in a Manufacturers contracted shop. Things most certainly have changed over the years, in both aspects, the manufacturing process and the repair procedure.
I had once a VW Golf, new of the lot. Two weeks later, (I put on a lot of miles in those days) my Air Conditioner didn't work. it just leaked somewhere. The dealer, passed me off saying it was over charged and they fixed it. Ten month later, 200 miles over the warranty, it failed again. The dealer kindly told me to fly a kite. I called the main office a few month later (didn't use the AC, winter months), after a little blah, blah, she offered to fill a die into the system. Then the dealer could find the leak. The car was 12 month on the road, (milage over limit)! So I ask and who is flipping the bill. I got the silent treatment and knew the answer. The problem was reported just 2 weeks after it got of the lot. Problem solved for everyone involved, except for me, I didn't get what I was promised. From then on either I pay big bucks for the repair or recharge every 6 month. Great service? This a very likely scenario in modern dealerships.

As to crank bearings, although it was rare, in my repair days, we would tear the engine apart and measure the crank and then the bearings (don't know if those tools are still available). Also, we would inspect them of wear or other abnormalies. If it was the cause of the clonk, we (the shop) would determine the bearing size and replace, do what was needed, so the customer would get the car back and could use it. The failed parts would be labeled stored and send back to the Factory.
But this is a long time ago, and as I know, things have changed in many ways.

My opinion about dealer repair shops(sorry), is such as to avoid them at any cost (the logo has to be paid for too), because of the complexity involved. Doesn't help me as a customer to garage my car because I have to wait for OK from the main office. If I drive the vehicle and it blows up, oh too bad, my fault. If you can, do it yourself. If you screw up (you better don't), the only one to blame is you, yourself, but the blame doesn't last very long.

So, no offense, I am very much aware of the changes that happened over the years. It's called "Optimization of profits" Profits alone aren't enough anymore, they have to be optimized... Someone higher up had that idea!

A friend of mine, paid a Mercedes dealership $1100.00 to get it smogged. Granted they replaced a plastic part and he has no idea what is underneath the hood.

Again, we are all just puppets on a string, we may know something but really can't do anything without asking big brother.
So, no offense.

I am NOT a person that wants everything for free!
I just want to be treated fair! It is probably safe to say, that I am not alone...

Cheers,
Norbert

Bump
 

Bump

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?

Oda
 

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...