Z4-forum.com

Hi all I'm experiencing a low speed low rev misfire or I'm assuming its a misfire.
2011 23i
If I'm blasting around and revving through the gears it runs fine.
just low speed low revs when it happens, seems to be getting worse !!
I've had it plugged into Carista but it doesn't bring anything up.

Was just gonna bite the bullet and change the plugs and coil packs, or is it more likely injectors ?

Not sure how old the coil packs are probably original along with injectors, Plugs are 4 years old but low miles.

Any thoughts / advice appreciated.

Cheers.

Unlikely to be injectors..plugs firstly then coils as most likely culprits..

Thanks for the advice.
That's what I'll do.

Try reading the codes. An error might be present that has not triggered the engine warning light

Just pull each coil and check for oil.
I had oil in no.4 plug hole, the cam covers warp, plug o ring seal leaking
Low revs was unstable at start until volts hit 14.4 (it runs battery volts for 3-4 seconds on start) or revving up engine.
No codes which baffled me at first.

After that usually a coil fault.

Any advice on Coil manufacturer there seems to be quite a few to choose from.

Pickster wrote: ↑Wed Feb 21, 2024 11:39 pm Any advice on Coil manufacturer there seems to be quite a few to choose from.

My personal preference would be Bosch, NGK, Nippon Denso and Eldor..FWIW

Thanks again for the advice, much appreciated.

Update, Swapped out the Plugs and Ignition coils this weekend.
Went with Bosch all round.
Took longer to get hold of the correct spark plug socket than to swap out the parts.
Car now running with no issues.

Pickster wrote: ↑Mon Feb 26, 2024 10:26 am Update, Swapped out the Plugs and Ignition coils this weekend.
Went with Bosch all round.
Took longer to get hold of the correct spark plug socket than to swap out the parts.
Car now running with no issues.

Good news.
So just swapped the lot in one go?
No idea if it was the plugs or the coils causing it?

My guess the coils..but if you are down there..a lot of effort to revisit if yiu guessed wrong..

enuff_zed wrote: ↑Mon Feb 26, 2024 10:30 am

Pickster wrote: ↑Mon Feb 26, 2024 10:26 am Update, Swapped out the Plugs and Ignition coils this weekend.
Went with Bosch all round.
Took longer to get hold of the correct spark plug socket than to swap out the parts.
Car now running with no issues.

Good news.
So just swapped the lot in one go?
No idea if it was the plugs or the coils causing it?

Probably a little overkill, but the Plugs were definitely 5 years old and the coils probably original 2011.
Plugs were £47.30 from GSF
Coils were £140.00 from Euro Car Parts.
Plug socket £4.50 Motosave
Peace of mind + £191.80