Bobsbenz1952

I purchased a 08 cls550 a month ago and discovered a miss in the engine after having the car a couple of weeks. This car has 78000 miles. I replaced the spark plugs but this did not help. I than took it to my MB dealer in Naples FL. and had them diagnois the problem. The mechanic did a compression check and discovered It had low compression Primarily on the right bank. My service advisor did a history check on this engine and discovered a Service Bulletin from MBUSA that this engine may have defective cylinder heads. For some reason when the engine gets hot the valves start to move around and create excissive wear to the valve journals. This can not be repaired and the heads must be replaced. This is a very expensive repair that I was not prepared to deal with.

I have spent much time trying to locate this Service Bulletin and I cannot find anything from MBUSA about this issue. Is there anybody who is familiar with this situation and could advise. Right now I am waiting for the CH's to arrive from Germany. As I said I am spending much money on this repair and I need as much information I can get to justify this. Thank you for all your help..... Bob.....

konigstiger

Check your PM.

rick hesek

Although MB is reluctant to discuss it, the valve guides on the 270, 272 and 273 engines, from 2007 thru 2009, have an inadequate heat treatment and hardening. They are prone to premature wear and this manifests itself on only the right side for some reason. I went through this with my son's 2007 E350.
The best way to diagnose is with a compression check which you have done.
I got a $1600 quote for a rebuilt head from MB. I also got a quote (and ended up buying) a right head from Metric Motors in LA. Great shop. Half the price of MB. The sales guy there said that they can't keep the right side head for the 350 engine on the shelf. 4 per week are sold.
Total repair $2800. The V8 will be more.
http://www.mercedesengines.net/

Let me know if you need more info,
Rick

Bobsbenz1952

Rick, thanks so much for taking intrest and replying to my post. I will give you a rundown of what has happened so far. Last Monday I took my 08 CLS550 to the MB dealer in Naples Fl. I decided to have them replace the 2 heads at a cost of 7k. It was my only option. After I came home that day a gentleman replyed to my post. After giving him my vin # ,he sent me me the Bulletin MB issued about the faulty heads. I was so happy to to see this come to me.
I than sent a copy to my service advisor who forwarded it to the service manager. I asked for some kind of restitution because MB admitted the problem. The service manager said the car was to old and had too many miles on it. I was very disappointed to hear this and decided I would not give this dealership any more of my money. The gentleman who sent me the post also sent me Andrew Noyes the General Manager of customer relations his email address. So I sent him a long letter about my situation and my MB dealers decision to deny my claim. That was last Wednesday when I wrote the email to Mr. Noyes. On Thursday I got a call from the dealership stating they would cover half of the repair bill, which amounted to 3500.00. I was very happy to hear this and I don't know if Mr. Noyes had anything to do with the dealers decision. So this is where I am at this point. My special thanks to Mr. Noyes if he is responsible for the change of decision. Again thanks for your help Rick.
Bob

rick hesek

You did well.
I'm happy to hear MB at least created a service bulletin for this problem and that you got some satisfaction.
After 30 years of Mercedes ownership, I have to say that their post sales support and strategy is weak. Aside of factory warranty, when we spend this much for a vehicle, at least acknowledge that there can still be lingering issues.
Another issue that exists in the '05 to '07 350 engines, that Mercedes will not discuss, is the "balance shaft" premature wear due to inadequate metallurgical attention. There is a class action suit in process and MB stands to lose a lot more than the cost of a few repairs, had they owned up to it. MB may acknowledge this, but not that I am aware of.
Regards,
Rick H

Donn111

Hi Rick,
Could you also send me a copy of that Service Bulletin, I just bought an 08 (two months ago)CLS 550 with 83,000. Hope I don't need it. All engines or a % of them?
thanks don.....

rick hesek

Hello Donn111,
Oddly so, I do not have that service bulletin. Konigstiger, I would appreciate your sending that to both Donn111 and myself?
The engines effected (in the US anyway) are the 300, 350 and 550 produced between 2006 and 2008. The service bulletin may specify what VIN's.
As you may have learned, the best way to identify the problem is a compression check. Get a compression check done. It may cost an hour or two of labor but, you will at least know how healthy your engine is. With 83k miles, if your engine is in this lot, I expect the compression would be out of spec. An MB mechanic did tell me that the compression, in one or more cylinders, needs to be off by 20% in order to send a misfire code. I believe the factory spec for compression is 140 psi, +/- 5% (cylinder to cylinder). You may have cylinder with low compression but not low enough to send a warning.
Many of us have spent $$$ replacing spark plugs, coils and injectors, trying to solve the misfire.

Rick

konigstiger

Here you go.

Donn111

Thanks for all the help.........don

rick hesek

Thank you, Konigstiger.
This bulletin outlines valve seat wear, which, according to Metric Motors, is due to inadequate valve guide hardness and wear. They use a replacement guide of their own with known metallurgical properties.
The guide wears, causing the valve to wobble which causes the seat to wear creating a leak and loss of compression. This makes sense to me and I believe is the root cause.
My engine is in the plagued range. A sad tale, if I do say.

Happy New Year to you all!
Rick H