CLOSURE!! MAJOR Misdiagnosis!!
Ok, here is the final chapter of this saga, and it has a happy ending. I still have my old (and very reliable) Volvo, so I just parked the BMW and marinated for a week or so, then took it to another reputable BMW shop - The Auto Shop in Birmingham, AL. Paul said it sounded strange that it would go from so good to so bad in such a short time with no symptms, so he checked it out. I drove the car home, then back to the Auto Shop and it didn't run as rough as I would have expected for a car that supposedly had a dead cylinder. Paul said the "dead cylinder" was in fact firing, so he did a compression check......175 psi, NOT the 75 psi the Bennette's Motor World had told me. He said it looked like the spark plug area had been pressure-washed recently, possibly by Bennette's to clear the oil from the valve cover leak that had puddled there. In doing this, the coil, plug connectors, and other electrical components were wet. So, he wiped it all down with alcohol and used compressed air to dry the rest. It is running like a top and I am breathing a huge sigh of relief. I love this car and I waited years to get one. I admit I am shell-shocked at what I was facing, but I'm going to keep driving it and hope to rebuild some confidence that, with some TLC, it can be a reliable everyday driver. (keeping the Volvo as a backup for a while longer...) Thanks again for the input!! The lesson I learned - low compression??? get a second opinion to confirm before you do anything rash.
PS - I sent an e-mail to the owner of Bennette's, explaining what had happened and saying I didn't want anything from him, but just to inform him of the misdiagnosis. He acknowledged the misdiagnosis and apologized. He swore they would never use water to remove the oil from around the spark plugs and he offered to pay the $150 the Auto Shop charged to fix the problem. I am satisfied that this was an honest mistake on their part.