Engine Performance problem
1998 BMW 540i V8 Two Wheel Drive Automatic 84000 miles
I replaced my valve cover gaskets this past summer because of oil leaking into the plug wells. I recently replaced all 8 spark plugs as well. Using the Peake code reader, the codes I am getting are " misfire detected, cyl. 5" & cyl 6, 7 & 8. Additionally, there is a " random or unknown cylinder" misfire along with " catalyst damaging" on cyl 5, 6, 7 & 8. I've swapped the ignition coils & the misfires are still on cyl 5 - 8. Also, the pre-cat O2 sensors were replaced about a year ago.
The check engine light flashes during wide open throttle beyond 3000 rpm & it struggles to rev past 4000 rpm - I took my foot off the accelerator after a while, thinking that I might do more damage if I tried to push it beyond 4000 rpms.
Thanks in advance.
Tuesday, December 29th, 2009 AT 8:17 PM