Just wanted to share an incident with my check engine light coming on a couple of weeks ago. I have a 2007 E550 and based on my serial number I had known for a while that I have the engine gear defect (thanks to helpful forum members).

While driving the car the check engine light came on one weekend but the car drove and felt just fine and in 2 days the check engine light went away on its own. I made a reservation right away for Monday when the light came on over the weekend. On Monday I hesitated taking the car in because by then the light was no longer on but I am so glad that I did take the car in.

The CEL turned out to be related to the defective engine gear and the dealer knew right away what the issue was as soon as they started diagnosing the issue. I was told on Monday afternoon that they had to order new parts and there was a lot of work involved to replace a part in the engine. I already had a copy of the DTB and verified with the dealer that was actually what they were working on.

I ended up getting the car back Wednesday evening and everything seems to be working fine. So glad I bought my car CPO as the warranty picked up the repair cost. Out of curiosity, I asked the cashier the cost of the repair as it wasn't printed on my no charge invoice and she said it was $4,100 So glad I had the warranty as I would not have expected a car with only about 35K miles to need such a big engine repair.

Anyway moral of the story is to to take check engine lights seriously and have it checked out as I might have done further damage driving the car if I ignored the light coming on. The other moral is to I guess try and have a warranty!

The only other defect remaining in my car that I know of has to do with whatever that causes the transmission to lurch as I think I am affected based on my VIN. Anyone have any info/DTB about that issue so I can keep an eye out for that as well?

 

Yea, tell me about it. Scary sometimes isn't it?

 

Man I'm glad I got the bluetec at this point.. the 550s were running at the same price when I picked mine up last year, and it was so tempting...

 

I still don't regret my choice to get a 550 one bit. I've driven the car for a while and still the engine never fails to put a big grin on my face whenever I come even close to pushing it. Very few vehicles on the road can come anywhere near it if I decide to push it so there is an element of safety in the power I have on reserve.

That being said I sincerely hope there won't be any other issues with the engine of this car. From all the research I've done, the engine seems to be bullet proof with the exception of this one gear issue and I'm glad to have had it fixed under warranty in case I decide to hold onto this car for a while.

Does anyone have the DTB for the transmission lurching issue? That's the only other factory flaw I am aware of for this car...

 

Is this 7 or a 5 speed transmission? Which version? I have had Bulletin resolved problems with engine and transmission mounts as well as having observed those who do not change their lifetime transmission fluid haha regularly.

Food for thought?

 

I have a 2007 E550 with 4Matic so I have the 5 speed transmission... I know my transmission is affected by a defect but would love to have the DTB on hand, as it came in handy when the engine issue came up.

 

I'm not familiar with the "defective engine gear" you are referring to, but doesn't the CEL light come on if there is an emissions related item not functioning properly? Was your problem emissions-related?

 

Far from it. This was a serious defect deep inside the engine. The check engine light can come on for a wide variety of reasons...

 

I have had some issues with light coming on, but honestly I don't take them seriously and that might be wrong of me.. But my 2 cents to this, the light gets armed for MANY reasons gas cap, misfire etc, however the car has to do a certain amount of PASSED circles don't remember how many (600 something) and it does one every so many times a minute, start-up's etc. in the end it comes down to a couple of days for light to disappear. Now if just one of the circles record's the same issue or another for that matter the light will not disappear, correct me if i'm wrong... So if the light disappears and does not show up again I don't see it as being an immediate problem or any, now if the light does not go away,,,, MB here we come!!!

 

+1
as long as your fluid levels remain constant, and you temp levels are good, it is not usually a big problem. get it to the dealer if it doesnt go away in a couple days....

 

I think your logic makes sense MOST of the time but in my car there was a serious issue with an engine gear. Though the check engine light went away in two days I would have likely done serious damage if I did not address the underlying cause which was deep inside the engine and needed over $4K of work. I think if the engine light comes on, at the very least get it scanned by someone who knows what they are doing so you can make a decision based on sound information.

Or you could take the ignorance is bliss approach but if you plan to keep the car for a while, might not be the best way to go...

 

Look at the AMG CL 55 etc. Category on this forum and search for Bulletins. Also, make are you drain your transmission fluid and replace the filter and clean the magnet every 40k miles.

 

OR YOU COULD BY AN AMG AND NOT WORRY ABOUT ENGINE ISSUES

 

I give. What's an engine gear that causes the CEL to come on?

 

I'll consider it when they offer an AMG car with 4Matic

Living on the East coast, there is no way I'll consider a car without 4Matic.

 

You're right. Instead you could worry about glycol contamination in the transmission in the AMG C32's, and in the SBC equipped cars - including AMG's - one can worry all night long about total brake failure.

Not engine issues, but issues (BIG ONE$), nonetheless.

 

I respectfully disagree. I do believe the engine light will come on for emisssions purposes. Usually a faulty sensor. I could be wrong. You keep referring to an "engine gear". Is that the engine or tranny related? Your above statement also seems to verify that your CEL light came off, even though your serious condition persisted. I don't think the two were connected. Again, I may be wrong, but can you specify which "engine gear" code triggered the CEL light as you stated in your op?

I do believe that one can have serious engine problems (a blown head gasket for instance, or water pump failure etc.) and the CEL light may never come on even though the engine is overheating.

I agree with you that regardless, once the CEL light comes on, there is a fault somewhere, and should be resolved or scanned for more info. asap.

Bottom line - I'm glad you resolved your issue.

 

Of course I don't know for 100% but I think the "engine gear" is with the engine vibration balancing weight system which is gear driven.

I also agree that the CEL is tied to the emission control systems but could there be a remote chance that the knock sensors on the engine could be used to sense the vibration that improperly driven balance sytem generates? I think this is a bit too far...

 

Can we just agree and let this go?

I think we both agree that if the light comes on it is best to have the code scanned to find out WHY the light came on. That's basically all I was trying to say...

And yes incidentally the light did come on due to something really awful happening in the engine. Though the CEL had gone away, they were able to scan the code and that's what lead them to diagnose and fix a pretty serious issue. And incidentally the Mercedes DTB pertaining to this issue specifically mentioned the CEL as the symptom to look for so it was very much connected.

Of course -- perhaps the CEL comes on mostly for emission stuff and I never disagreed with that. All I was saying is have the code scanned so you know for sure.

 

A knock sensor miscommunication with engine management system would throw a code.