pmunhutu

Hello,

I am new here so please forgive me if this is in the wrong place. My bmw is misfiring. I replaced my spark pugs with NGK platinum plugs PLZFR6A. Car worked fine for 2 days and I drove ~200 miles. After work I started up my car and it initially sounded ok then it started to shake. It was a very cold day. I managed to drive home but the car had significant loss of power.

A mechanic inspected it and told me you have an oil leak caused by a bad valve cover gasket and probably have oil in one of the plugs. So in the interest of saving money, I replaced the valve cover gasket (that was painful) and torqued manually. I did hear two snapping sounds but the bolts were all firm (snug + 1/4 turn ish).

Fired the car up in all glory and it was misfiring. Ok I then searched online and I have done a vacuum test using brake fluid cleaner, and I replaced all the plugs and moved the coils to different bays. Same condition. Had the codes read P0301, P0302 and P0303 - Cylinder misfire condition for cylinder 1, 2 and 3 respectively. I also have a code P0171 - Fuel trim bank one condition.

So I pulled out the coils one by one with the engine on and 1 2 and 3 are dead. Now the condition manifested itself 2 days after I had changed the plugs. I have changed the plugs again today - NGK IRIdium ILZFR6D11 but still no improvement. What should I check?

1) Is it an o2 sensor? (Would it cause all bank one plugs to fail?)
2) Is it the DISA - just read about it.
3) Something has failed specific to plugs 1,2, and 3. The others are fine. Please help....

pmunhutu

Hello,

Just a little more info, my cat was glowing red for the cat connected to bank 1 (cylinders 1, 2 and 3). When I revved the engine though, the cat cooled and stopped glowing. But the glowing seems to occur after starting it and allowing it to idle. Not sure if that points to anything specific.

Hopefully someone here can advise me.

nomis_nehc

Wasn't quite clear, did you change the coils? I had some of the symptoms you described earlier this year, replaced the coil and everything was good.

pmunhutu

I did not change the coils but I mixed them around to try see if one was bad but I can pull coils 1-3 out and there is little change in the idling of the vehicle.

nomis_nehc

I don't know how changing them around is suppose to help if the code reads basically that 3 coils could be bad...

pmunhutu

Ok, let me go perform this test so I can give you a definitive answer, I was pulling one at a time:


But note, the codes taken at autozone read multiple misfires in cylinder 1, 2 and 3. Would 3 coils go bad all at the same time? Could the initial platinum spark plugs I put in have messed them up? I got them from realoem.

pmunhutu

nomis_nehc, you are a genius mate! Spot on, turns out cylinder 1 and 2 had bad coils. But for me here is the mystery, does two coils going bad at the same time indicate another issue. Note this happened two days after putting in new plugs - NGK platinum plugs PLZFR6A. The BMW dealership told me that those plugs might have caused this, is this possible?

Anyway got two new coils, NGK IRIdium ILZFR6D11 plugs and service engine light will be switched off tomorrow so hopefully everything is good. Car drives great. Thanks for all the help.

nomis_nehc

Glad your problem is resolved. I can't comment on whether it's an indication that something else is going on, but it isn't that uncommon for coils to fail. There actually are more instances discussed on the 3 series.

Anyway, just wanted to help and impart some wisdom based on my own experiences.