After 188k and putting up with a couple of years of oil leakage, I brought my 1991 740 into a local repair shop to get the rear crank seal replaced. The car ran great when I brought it in but had an oil leak. When I picked the car up, the oil leak was fixed but the car ran very bad. There was a knock at engine load, the car idled rough in park and a miss developed, the car sometimes killed when going into drive from park. I have brought the car back to the shop several times and I usually get a reply like, "sounds like an engine problem and we didn't touch the engine; but let us look at it." I know that the problem developed when the seal was replaced.

Can anyone advise me if they know what the problem could be here? I understand that the flywheel must be properly postioned on reinstallation. Could this be a problem or could some other problems similar to mine develop if the seal, transmission and other parts are not reinstalled correctly? These guys claim to be import, including volvo, specialists, but I have my doubts. I guess this is what happens if you don't do the work yourself!

Thanks for the help.

You have it correct, the only mistake which could be made is to index the flywheel or ring gear incorrectly. It sounds like that may have happened. I suggest that you verify the flywheel or ring gear indexing by the following method:

Disconnect the battery and remove the starter. Once the starter is removed, position the engine on number 1 cylinder TDC and the two blank holes or slots will be visible in the starter opening, lined up with about the bottom of the starter openning, on the perimeter of the flywheel or ring gear. If you can't see the lack of holes, you can feel them with your fingertip. This is an easy job and should take you less than an hour if you have tools.

The cars with LH 2.4 Jetronic have 58 holes(slots)in the perimeter of the flywheel(ring gear). There is room for 60 holes, and two holes and not made for the purposes of indexing the ignition system.

Please let me know what you find.

John-

Yes, the flywheel was not indexed correctly. After telling the mechanic that it could only go on one way, he pulled the transmission back out on Friday and said he was off one bolt hole. Car now runs great and no leak!

Thanks.

Just as I thought. Few brickboarders know the flywheel indexing can be checked by removing the starter.