Power delivery issue

[meitme]

Hello; I'm quite new to Z4 ownership but seem to have an issue with the car today: I have a 3.0 coupe, and under harder acceleration today the power was sort of coming through in waves- almost like the old bunny hops when we were all learning! Kind of throbbing power delivery is the best way I can think of describing it, but not in a good way! The traction control wasn't kicking in or anything so I think it's engine-related.
Is this a known issue with Z4s? Do you think maybe an injector issue or something electronic perhaps?
Thanks in advance!

 

[AveZ4coop]

Definitely worth reading your fault codes, but sounds like it could be a coil pack on its way out. A replacement set off ebay is around £120.00. Worth changing spark plugs too.

 

[ph001]

Won't be injectors. As above, start by reading fault codes - if nothing, change out the plugs and coil packs. Then you are probably into things like the AFM, eccentric shaft sensor or valvetronic motor. Make sure your battery is good too - Z4's don't like old batteries.

 

[meitme]

Thanks guys: coil pack sounds a decent shout. I had one go on my old Audi and although it felt different on that (the engine suddenly wouldn't rev and lost a lot more top end power, but then I guess it had fewer cylinders!).

How do I see the fault codes? Does that require a diagnostic kit being plugged in?

 

[AveZ4coop]

I had a coil pack fail on my 3.0l, started off as an occasional stutter under hard acceleration, no fault lights or error codes. I ignored it (as you do) and then on a long trip on the dual carriage way it failed totally, engine light on and a horrendous stuttering under anything but light throttle. Luckily these engines shut down the injector when the coil fails to prevent bore wash (I hope this information I was given is true) so I could drive the car home. New coil packs and plugs and all was as good as new (the engine fault code reset itself on first post replacement start-up, so code reader not needed for this). Many trouble free miles have since been covered.

You will need a OBDII reader (available off amazon or ebay for around £30) to read basic codes. One of these will show you where the fault lies but may not be able to reset them.

 

[meitme]

I had a coil pack fail on my 3.0l, started off as an occasional stutter under hard acceleration, no fault lights or error codes. I ignored it (as you do) and then on a long trip on the dual carriage way it failed totally, engine light on and a horrendous stuttering under anything but light throttle. Luckily these engines shut down the injector when the coil fails to prevent bore wash (I hope this information I was given is true) so I could drive the car home. New coil packs and plugs and all was as good as new (the engine fault code reset itself on first post replacement start-up, so code reader not needed for this). Many trouble free miles have since been covered.

You will need a OBDII reader (available off amazon or ebay for around £30) to read basic codes. One of these will show you where the fault lies but may not be able to reset them.

Thanks; that's very helpful. The starting-as-a-stutter thing sounds like it could well be the case that it's a coil pack. I believe it's supposed to have just had a new set of plugs so they shouldn't be the issue with any luck!