Granted, the temp gauge was normal, no oil lights etc. - The oil was clean, the coolant was clean and I saw no signs of exterior damage. Anyway, I knew the motor had been replaced & thought could this be a spun main bearing? - It sure sounded like it! - Anyway, after a lengthy tow to the dealer(I towed it there because I thought it might be a bearing & maybe they would make good on a replacement motor-maybe) - My car spent the night there and the dealer called to tell me that there was a valve on the back of the intake that went bad(whew-what a relief). The valve caused my O2 sensors and plugs to foul(this caused the check engine light). Anyway, long story short, They gave me an estimate for $480 in parts and $720 in labor - totalling to $1200!!. My service manager there was really cool about everything and gave me the parts list - he knew I had done quite a bit of mechanical work (transmission & A/C) before and told me that if I had time - maybe I should do it myself - I called BMA & they got me all of the parts for Half of what the dealer wanted - I got OEM too!! I'm waiting for the parts to arrive right now(Fed-Ex) & it's not going to take as long as expected.
While waiting for the wrecker to show up and take me home, the General service manager(not my guy) - started talking to me and insisted that I couldn't do this job myself and I didn't know what I was talking about - whatever. I insisted that I did all of my own complete replacement on suspension, brakes, tranny, diff, A/C work in my driveway - he laughed and said that this was FAR harder than any of that!! He went on to tell me that it would take 5 hrs just to remove the valve - it took 1hr!!!
Trying to scare the customer into service . . . BTW, the whole time I was fretting on the interstate with the smoke coming out of my exhaust there was a new E39 M5 sitting behind me - embarassing, but . . .
Anyway, if this problem happens, check the valve on the back of the intake - I'm not sure how to diagnose the valve itself, but the symptoms are as I described above.
Cheers! I'll post pictures later today!
Thanks Bruno for pointing the way to BMA!!