[garyhgaryh]

My 2008 335i has recently started to act funny when I floor it.
At boost, the car starts to stumble/hesitate and the check engine light
comes on. I've been trying to figure this out, but have not had any luck.

The car has absolutely no modifications and has been in for a fuel pump
replacement. I'm not sure if I'm overboosting or detonating. Perhaps my wastegate linkage has been disconnected (haven't check that yet).

It all started (and this could be coincidence) when someone got gas for me and got mid-grade instead of premium (yeah thanks for being cheap). I figured next fill up should cure it - just get premium. No dice. This may or may not have been a coincidence, but in anycase, my car doesn't like to be under load or under boost.

Not sure if this is a common issue with an easy fix, but if anyone can help, I'd appreciate it.
Gary

[bimmerben335i]

Pull codes, I garuntee you it's the injectors. Common problem with 335s. Just had 3 of my injectors, coil paks, and plugs replaced under warranty. Issue gone! Had the same issue your having. It's in 4th-6th when floored. Then it's a rough ride till the ecu reflashes. 99.999999999% positive this is your problem. Pull codes to be sure first.

[saini7]

its your spark plugs... i had these exact same things happen to me a couple weeks ago, changed out the spark plugs and runs perfect now !

[subieworx]

Spark plugs then coil packs.

[ctuna]

Walnut Blasting?
due between 60 and 90k

[garyhgaryh]

Thanks all! I'll change out the cheapest components first.
1. spark plugs
2. coil pack
3. injectors

I already had the injectors changed out by the dealer. Now my car is out of warranty.

I will pull codes this week.

Thanks all for the help. What plugs are you guys using?
Gary

[garyhgaryh]

I finally found time to work on this issue and in jan/feb changed my plugs with the Bosch equivalent. That fixed my issue completely.