Ag E55

Ok, I am in hopes that someone can shed some light on to my situation...about a month ago, I started to get CEL, found out that I was having cylinder7,8,9 were misfiring....gone through whole bunch more test and came to conclusion that I needed to replace, the left bank coil pack, wiring harness (due to oil leak), o2 sensor, MAF sensor, plugs, and injectors.....after almost $5K in repair bill, it still misfiring in cylinder 8 and 9....I am totally lost here and so is my mechanic.....any advise would be hugely appreciated it. Help out a fellow member please...any certified technicians out there with some idea?

Thanks in advance.

OLDSCHOOLRICE

Try swaping injectors around and see if the missfire follows the injectors. I have seen it happen on a couple of 65 engines.

Ag E55

Thanks for your input....I will have the mechanic check the injector.....thanks again for sharing.

benz-tech

if your car is a non-turbo S600, the cylinder shut-off system has been known to be problematic and cause misfires on the left bank. a dealer can check and change that coding. BUT, that misfire might be a little more random than what you're experiencing. i'm hoping the oil sensor that causes oil entry into the harness was replaced already. i seem to recall a campaign to that effect.
unfortunately the above only applies to '00-'02 model years.

i see that oldschoolrice is a fellow dimer. i smell a thread jack, whacha got in it?

Ag E55

My car is in fact a 02, non-turbo. I was also told that cylinder shut-off system issue and my indy mech has verified that my car alrady was flashed with the update software. As for the oil sensor, it was also replaced by indy mech. As of yesterday, I have taken the car to the dealer (Rasmussen Mercedes here in Portland)....had a lengthy discussion with the service advisor and the shop forman. They happend to think it would be a simple fix and it turned out that they knew all about my car and the problem. My indy mech was a formal employee for years and he has been calling getting input from the shop forman. I am in hopes that it would be a simple fix and inexpensive....I don't think I can handle any more repair bills on this car. Thanks for sharing and will post what they find.....

benz-tech

i've met the shop foreman and their diag tech. very sharp guys, they will fix it.

Ag E55

it turned out that you were right......they ran some test on the injector read out and found that the injector for cylinder 7,8 and 9 were bit off. So, they took the fuel rail off and found that it had some debris....they changed the injector and the car runs so much better. I can still feel bit of misfire but no CEL comes on and I will see if it will pass the DEQ. I am much relieved but can't say that i am happy that it cost me another $1200 to get this point. Also, found out that my indy mech put in a wrong injector in cylinder 7.....lost all faith in this guy. Going to get some money back from this guy for sure. I kept the work order open just in case with the dealer.......thanks again for everyone's response and input. I love this forum.