E320 Rough Idle / Egr Problem
I have posted here before with unique problems with my 95 E320, but am now totally stumped..........as is my mechanic.
I have been having an intermittent rough idle problem for several months now. Then, about three weeks ago, the CHECK ENGINE lite came on. I took the car in to my mechanic who is usually very competent.............to unrabel both problems. The computer codes indicated an EGR problem, which may or may not be related to the rough idle. We cleared the codes and they came on once again in about 5 days. Same indication.....EGR valve. I tentatively scheduled to bring the car in the following week to have them check out the EGR and the tube that is known to plug.
Over the weekend, I decided to do some work to sort out the rough idle problem. In researching the archieves, I found a number of threads where Arthur Dalton provided insight to the things that can cause a rough idle. One of them was the connector that connects the plug coil with the spark plug that lies just below the coil. Since I know that none of these had everr been changed in 140,000 miles, I felt it a cheap change to make.
So, I replaced the three connectors below each of the coils, and the car fired up fine. I went to test drive it, and about a block into the drive, the car suddenly started missing very badly. limped home and had the car towed into my mechanic.
"When he pulled the plugs, he found them all completely wetted with fuel. Since I had replaced the plugs within the last month, I find it hard to believe that the plugs are at fault.
However, my mechanic replaced all the plugs and cleared the codes and the car fired up fine. He drove it for a day and pronouched it cured; however, when I pecked the car up, the CHECK ENGINE light came on once again. Though the engine is not misslng nearly as badly as it was when I had it towed in, both my mechanic and I are at a loss. He kind of threw up his hands and suggested that I take it into the dealer who had better diagnistic facilities.. To me, that sounds like an open checkbook.
I would appreciate any insight anyone could provide..........especially, if A. Dalton reads this note!