M271 common engine fault?

[Trotter]

Hi, I've recently bought a 2003 230 kompressor with 41 k on the clock, and it seems i have a problem. On tickover and in the"Park" position (but not in "drive" strangely enough ) after about 30 seconds my car starts missing slightly on cylinder number 2- enough to trigger the engine light, if i turn the car off then restart it she runs like a dream (providing i don't put it in "park" or neutral.) Ive got a contact at the main dealers who reckons it's a valve not seating properly and it's a common fault on this engine - and it's a cylinder head off job. When i explained it had only done 41k etc he said they've been known to go at 10k. Has anyone on here any knowledge of this fault?

 

[BlackC55]

Yes.

I have done a few. Before getting this deep get it diagnosed properly as it may just be a coil or spark plug issue. The rough running threshold can be de-sensititsed (right word?) too with the Star.

 

[Trotter]

Yes.

I have done a few. Before getting this deep get it diagnosed properly as it may just be a coil or spark plug issue. The rough running threshold can be de-sensititsed (right word?) too with the Star.

Thanks for the reply, excuse my ignorance but what's the star?

 

[Smatt]

This is the software system MB use to diagnose & alter software coding on the cars' built in operating system.

 

[buellwinkle]

Hi, I've recently bought a 2003 230 kompressor with 41 k on the clock, and it seems i have a problem. On tickover and in the"Park" position (but not in "drive" strangely enough ) after about 30 seconds my car starts missing slightly on cylinder number 2- enough to trigger the engine light, if i turn the car off then restart it she runs like a dream (providing i don't put it in "park" or neutral.) Ive got a contact at the main dealers who reckons it's a valve not seating properly and it's a common fault on this engine - and it's a cylinder head off job. When i explained it had only done 41k etc he said they've been known to go at 10k. Has anyone on here any knowledge of this fault?

This is very common for the first year of the M271 production. It's a poor head design that causes excessive carbon build up on the exhaust valves until they no longer seat right. You need the new design cylinder head, in the U.S. that's about $2,000 and usually an equal amount for labor. Another hellish problem is the Valeo radiators used that year, they crack internally and leak coolant into the transmission oil, soon after you need a new transmission and of course a new radiator. Add to that the service campaign they did about the 2 hoses that went bad but costs $500 to replace because you have to remove the intake and s/c to get to them and the TSB on the 2003 camshaft sensors leaking oil into the engine's wiring harness and costs thousands to replace the harness and O2 sensors and of course the 2 cam sensors. Basically, you are screwed. MB of course is willing to help by selling you the new C300, a very nice car.

There's no short cuts I know of that will solve the problem permanently. The short term fix is to try GM Top Engine Cleaner, a solvent that cleans the carbon deposits. You can google it and get more info. Maybe you can get it good enough trade in for a new car. Personally I would feel bad selling it to a person, trading it in to a dealer makes it less personal.

 

[Trotter]

And guess what guys, my problem was just a dodgy spark plug on cylinder number 2 She runs like a dream now!

It was a technician at MB putting the spooks up me with possible horror stories.