MikeWhitney wrote:
So as I mentioned it was not running right, seemed like a bad cylinder. Did compression and something was funky with cyl #6 (120# vs 170ish for the others). Pulled the valve cover to check cams, looked good, replaced leaking valve cover gasket while I was in there, new plugs (lots of oil inside the plug holes from bad plug hole gaskets), back together and .... still misfiring or running on 5 cylinders.
Said screw it, tossed in a new radiator, and went for a drive. Still misfiring and clicking loudly a few times up and down the street. Got tired of pussyfooting ... ran it up the revs and BAM she cleared her throat and is running great. I mean really great, the old M50TU has more power than I remember. I suspect that one lifter or valve stem was sticking on #6 and she just needed an "italian tuneup" to free up.
Otherwise it drives great. Floaty and a few clunks from a 20 year old suspension as to be expected. Trans, shifter, brakes, steering, etc all feel nice. She's a keeper.
And the best part ... no CELs!
My M5 does this if it sits for 3-4 weeks without being driven (don't ask - doesn't happen any more!). The Italian tune-up works every time.