[325isBMW1988]

Driving home the other day, not beating on my car at all, the engine began sounding like a cylinder wasn't working. Woke up the next day with the intention of finding the problem.....5 days later still not working.

It starts right up but idles erratic, almost like its going to die. Ran a scanner tool and got the following codes:

P0306 Cylinder 6 Misfire
P0155 O2 Sensor Heater Circuit

My thought is that an 02 sensor alone would not make one cylinder misfire/fail. I took apart the whole intake (except for manifold) and cleaned everything from hoses to ICV. All hoses and electrical connections are in top condition. Ignition coil on cylinder 6 was replaced and swapped plugs to see if they were faulty....both fine.

Anyone have any idea to what my problem could be?

My next step is to take apart the fuel rail and look at the injectors....but could that really cause my problem?????

 

[325isBMW1988]

BUMP! someone must have some input? any! really! lol

 

[witeshark]

Maybe it's as simple as a bad lead to cylinder 6.

 

[learoy E30]

Firing

Hi i had a similar problem with my 323i 99 model,i was driving home & it started missing felt like it wanted to cut out and die,i went home replaced fuel filter and checked for air leaks as well as elecrtonics ALL was fine.To solve the problem i used a fuel treatment cause the diagnosis machine would'nt pick up varnish coating blocking the injector or injectors.Its been fine ever since.

 

[325isBMW1988]

Hi i had a similar problem with my 323i 99 model,i was driving home & it started missing felt like it wanted to cut out and die,i went home replaced fuel filter and checked for air leaks as well as elecrtonics ALL was fine.To solve the problem i used a fuel treatment cause the diagnosis machine would'nt pick up varnish coating blocking the injector or injectors.Its been fine ever since.

My guess is that it is an injector problem so I will definitely try that first before buying an injector.

Any recommendation on the brand of fuel treatment?

 

[325isBMW1988]

Maybe it's as simple as a bad lead to cylinder 6.

A bad lead? Like the wire that plugs into the coil?

 

[witeshark]

A bad lead? Like the wire that plugs into the coil?

yup

 

[325isBMW1988]

Well I ran some injector cleaner and switched injectors to see if the problem followed cylinders. Ran the scanner and it didn't mention any misfire, cleared the codes. Drove around the block, ran the scanner again and Cylinder 6 Misfire came right up.

I'm guessing now, after everything I've checked over, that it must be electrical lead cutting something out (as witeshark mentioned above).

And Witeshark, is there a way I can tell if the lead is shot? I have separate ignition coils for each cylinder so I haven't dealt with this set-up and wouldn't know how to test it.

Thanks for helping me out!