ignition coil- can i change one, or have to change all?

[pav]

Hi guys,

Following on from my previous thread about the car idling rough and engine management light coming on, i called out the AA on a friends policy, and the car threw up 2 faults, one was a failed igntion coil and the other the cam shaft sensor.

My question, is can i change just the one failed ignition coil, or do i have to change all 4 (4 pot engine, 318)? The AA guy recommended i change all 4, but when doing a search on here, i notice some of you guys only changed one?

Also, what does the cam shaft sensor do, as i presume the problems in car were only caused when the coil failed, so i must have been driving around for a while with a faulty cam sensor? or do they generally blow simultaneously?

cheers

[Styler]

you can change just the one, but if one has gone maybe more will fail do better to get all of them changed. They are not too expensive only about £20 for each ignition coil.

[adood84]

When BMW changes it even under warranty they usually change the lot , thats what they did with my car

[Stock323iSaloon]

i think BMW uses the Bosch ones and you can get them from GSF/ECP cheaper. If you're flush, go for Plasma Direct M:cool:

[Mud]

you can change the one, but might as well change all of them and its an easy job to do yourself as well.

[pav]

Replaced the failed ignition coil with a new bosch one this lunch time. The misfire has reduced a great deal, and the revs have dropped to their normal level, but the car is still vibrating more than normal, like there is still a notable misfire/vibrating of the car, albeit a lot less than before replacing the coil. Definitely not 100% ok. The engine management light is still on, . Does anyone know if the remain problem will go if I reset the fault codes, or is it likely that there is another problem.

Apologies for all the questions, I have searched but can’t come up with anything.

Cheers

[danch]

pav,
Have you replaced the camshaft sensor, this will be the cause of the problem you are currently getting.

Think they are about £65 from the dealer & on my 330d took 10 minutes to replace.

Think its part 4 here (http://www.realoem.com/bmw/showparts.do?model=BX92&mospid=47612&btnr=11_3296&hg=11&fg=15&hl=7)

Dan

[Black Sabbath]

^^ What he said :)

[pav]

Thanks guys, appreciate the help. from what i can see in that diagram, and posts over on E46 fanatics, there are two camshaft sensors, which one should i be replacing?

[danch]

I would start with item number 4 Camshaft sensor, it is the easiest to replace, there is also a crankshaft sensor which can go as well, but best to replace the top end one Pav.

HTH

Dan

[pav]

Just had the AA guy out to run the diagnostics, he cleared the failed ignition coil one, and we took the other sensors out one at a time to confirm which of the camshaft sensors it was. Looks like an easy fix, gonna get the new sensor tomorrow.
Must say, both times i called out the AA guys, they were both very helpful and willing to look into the problem thoroughly, despite being out in the rain and the cold. top lads.

Cheers guys.