Engine Pulsing

[GregE85]

Evening Z4 people,

I hope everyone managed to enjoy the great weather over the Bank holiday weekend?!

So i have a niggling issue with my 2006 E85 2.5si, it seems to lightly pulse or what feels like throttle feathering when trying to hold a constant speed. If the engine is under light load its a bit more obvious? Heavy load its not noticeable at all which is slightly confusing?

I have had replaced both Vanos solenoids and all 6 coil packs after a cut out issue which threw some codes on my c110+ BM scanner (at which point it did not have this issue). Spark plugs were replaced around a year ago (before i had the car).

I haven't had any codes thrown whilst this niggle has started, which i think is strange?

i'm planning to take it to a garage for a diagnostic read next week. Although i'm hoping the abundance of wisdom here may shed some light on the issue!

Also are there any of you guys commuting A303/A34/M3??
I see quite a few Zeds on my daily drive!

Cheers

Greg.

[Mike6]

Cracks on the intake rubber, dirty MAF ??. Has air filter been changed. Mine went 10 years of BMW dealer servicing before I noticed it was rather dirty and had never been changed.

[GregE85]

Cracks on the intake rubber, dirty MAF ??. Has air filter been changed. Mine went 10 years of BMW dealer servicing before I noticed it was rather dirty and had never been changed.

No cracks on intake that i can see, although i will have another good look over it. I've read mixed threads about cleaning the MAF?! so have not cleaned it. Air filter was replaced last year with plugs, again i'll check.
Thanks

[ph001]

Either eccentric shaft sensor or valvetronic motor would be my guess. The latter usually gives a rough idle as well though.

Take the top cover off the engine and you can see the sensor. Any oil leaking in or around it usually means it’s stuffed but they can fail even without that.

[GregE85]

Either eccentric shaft sensor or valvetronic motor would be my guess. The latter usually gives a rough idle as well though
Take the top cover off the engine and you can see the sensor. Any oil leaking in or around it usually means it’s stuffed but they can fail even without that.

I think we have a winner!!
I’ve not noticed rough idle but then again I’ve not had anything to gauge it against? It seems ok with idle occasionally a blip here and there but settles. Looks like it’s the eccentric shaft sensor?!?
Air filter looks good and no splits in the intake rubber.

Cheers guys! Thank you for the advice, Now where’s that money tree gone?!?

[ph001]

Yep, any oil around that sensor is usually a sign that it needs replacing. Not too bad a job I don't think. Let us know how you get on.