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View Full Version : MISFIRE On ALL 8 CYLINDERS HELP


SuitedKings
09-11-2012, 08:23 PM
BMW is trying to charge me $7000 to fix my 2004 BMW 745Li because it is "Misfiring" through all 8 cylinders. They're also stating that my secondary air system has a fault. My car has 69K miles on it and I've had the coils and spark plugs checked already. Please help!!!!!!!!!!!!

sirstopher
09-12-2012, 01:05 AM
Post this in the e65 section

SFbay
09-12-2012, 09:56 AM
BMW is trying to charge me $7000 to fix my 2004 BMW 745Li because it is "Misfiring" through all 8 cylinders. They're also stating that my secondary air system has a fault. My car has 69K miles on it and I've had the coils and spark plugs checked already. Please help!!!!!!!!!!!!

Interesting;)
So how did it happen??? Just out of nowhere???
I guess valve cover gaskets are leaking causing misfires bc coils are flooded with oil. What does the dealer say??

chrisrees
09-12-2012, 10:25 AM
Won't drive if it needs all 8

coole65i
09-14-2012, 11:59 AM
BMW is trying to charge me $7000 to fix my 2004 BMW 745Li because it is "Misfiring" through all 8 cylinders. They're also stating that my secondary air system has a fault. My car has 69K miles on it and I've had the coils and spark plugs checked already. Please help!!!!!!!!!!!!

What are the symptoms? Is it idling rough? How do you know that all 8 cyl. are misfiring? Did the stealer show you the actual codes your car is throwing? A $40 code reader can tell you which cylinders are misfiring. Even if you had to redo all valve cover gaskets, coil tubes, coils and plugs, it's NOT going to cost $7k. They are all DIY items. If you are not a DIY'er, you can find an indy BMW mechanic for a lot less. I did this job myself for my 545i which has the same engine as your 7 and recently changed the plugs on my LCI 7 as well.

southfla305boy
09-14-2012, 09:56 PM
*****************CHECK YOUR PCV VALVE...ITS ON THE TOP OF THE VALVE COVER..SHOULD BE 2 (one on each)......try this: Idle the car, open oil filler cap, there should be A LIL bit of vaccum/suction.. if it stalls out, then they are bad...$70 for both at the dealer..


Im a Mechanic and tried new coils, plugs, compression check and ALMOST changed the computer ($900)...03 745Li misfire cylinder 2 with fuel cut-off

now she idles CRAZY SMOOTH......any questions let me know Good Luck

southfla305boy
09-14-2012, 10:00 PM
*******************CONTINUED********************

forgot to explain what was happening.. when they go bad, there is EXCESS pressure in the crankcase which was throwing off the crank sensor, therefore sending the wrong signal...as SOON as i replaced them, it started up like nothing happened...She used to stumble at idle and worse when in gear at a stop light. But u WOULD NOT feel it as u drove or even put your foot down...just at idle