cylinder misfire...
 

hey guys, i haven't been on in a while anyways and unfortunetly back needing a little help........

i reseted aoil change in my car, and while i was at it scaned it, it said that a misfire was detected in cylinder #2...so i replaced all the spark plugs just in case but still shows up, car still runs the same....what do i check next or what it might be?

thanks all of you in advance!:thanks

Have the ignition wires been changed?

no wires in his car, it may be your coil pack

Hi

I have noticed on other cars with coil packs that the when removing coil packs that they can crack internal causing a miss also the lower parts coil breaks off easily. I don't know if bmw coil pack do this. I haven't removed bmw coil packs yet

could be a weak coil and/or crank trigger. could also be low compression in that particular cylinder usually caused by mileage/wear

I am also chasing a miss on my 525i but do not have a tool to read the codes. I am waiting to find out ohm values and terminals to test the coil packs individually.

hello folks
 

hi everybody, i am a fan of the marque since 2004 when i bought my first bimmer, it was a e24 M6 , then came a e38 740i sport, and x5, one e39 528i sport,two e36 series one is a estoril blue m3 and now i have 2 e32 7 series, and a e34 m5 which is my every day ride, well cheers to all.

i have problems with my e32 735i, i have a hesitation while acelerating, check all the bells and whissels and nothing, no power like the other e32 735i. I was thinking on the fuel pump because sometimes the engine takes a while to start, if i leave the key on the on position for 3 to 4 seconds then start position the car fires right up. any suggestions

Regarding the first problem, I have seen camshaft failures cause an unidentifiable problem as such.

A friend had a 2003 GMC truck, 5.3 vortec engine. He had it to the dealer 5 times under warranty. New injector, computer, coil pack, plugs etc. Finally it failed completely after the warranty was out and ended up getting a motor because of it. In this case the roller on the lifter apparently failed first, taking out the camshaft and causing a cyl. 7 misfire code on the way. I hope this doesn't help, as I wish mechanical failures on nobody.

I've been told by supposed mechanics that a mechanical failure could not cause a misfire code, but they're wrong. JMHO.

Also, go back to the basics. What did the old plug on #2 tell you? Lean, rich, normal, excessive wear, etc? The four whores (Suck, Squeeze, Bang and Blow) always apply....and I tend to overlook that as much as anyone. Leaky intake manifold gaskets sucking air can cause this, faulty fuel injectors, valvetrain failures, low compression from a washed-down cylinder(from leaking injector), etc. I hope it's something simple though :P.

Check thoroughly for vacuum leaks. Brake cleaner(make sure it's not the non-flammable stuff) or ether is a valuable tool for this(spray suspect areas). Be careful to keep spray away from the air filter inlet, as this can give you a false reading. Switch two coil packs(if they're individual to cylinders) and see if it moves. This will ID a faulty coil pack. Switch fuel injectors(this will cost you a couple o-rings), this will ID the injector. If it maintains cyl. 2, run a compression test across all cylinders. You should be able to ID the problem by then, with minimal cost. Also, you can put a vacuum gauge on it. I don't know what a normal reading is on those cars, but a misfire may cause a fluctuation due to lack of scavenging on the misfiring hole.

I don't mean to sound like a know-it-all, just trying to help.