97 C280 problems
For the past couple weeks I noticed the car does not idle very well. When stopped and in gear, the idle keeps varying between 750 and 450 rpm and it feels alsmot like the engine is about to stall. When I shift to neutral, the idle goes higher but still varies a little.
Last week while driving home, the engine started running very rough and the CE light came on. I scanned it and came up with cylinder 6 misfire. The plugs have never been replaced so I bought a new set and replaced all 6. The car ran fine for a couple days, then yesterday the same thing again. I scanned the codes, same misfire, cleared it and its back to OK for now but still has the rough idle.
Is there anything else I can check in the car? Could this just be a case of bad gasoline? I'm thinking I should put some fuel-injector cleaner in with the next fillup.
The car has only 30k miles on it.
Also, does anyone know if there is a service manual available for these cars? I plan to do all my own maintenance on it and a manual would help. For one thing, how do you change the trans fluid?
Thanks for the help.
If the tune-up doesn't help, it is possible that there is a vac. leak somewhere that is causing the rough idle, but the misfire code would lead me back to the tune-up idea.
Check with your dealer to order the repair manual. It is a bit more expensive than a Haynes or Chilton manual, but it goes into much greater detail.
What would I need to change/replace for the tune-up?
For the rubber boots on the plug wires, are those part of the wires so would they be replaced with a new set?
For the manual, I can't find one at either chilton or haynes. Even Mercedes doesn't offer one for the W202.



