" So not cool. "

" Okay now I am getting a litte upset here.

I pulled the engine cover off to check their work. Two bolts holding the cover on are missing. Okay no big deal.

Then I notice my injectors don't look so new. My paper work clearly states they replaced all 6 injectors with part# 13538616079, except all of my injectors are the old part # ending in 261. "

" I watched the live feed AFR all the way to work. Cruising looked okay, average around 14.5-15 with an occasional 16 flashing on the screen. It will come down to 12-13 with a bit more throttle. Didn't do any heavy throttle pulls though.

Put in an order for O2 sensors. Going to check under the engine cover tonight to see if they left something loosely plugged in when they did the valve cover gasket replacement. "

" Tried to push the dealer to be more proactive about this issue and the SA sent the following response:

"In my almost 5yrs as a tech never was there a time where a bad O2 sensor resulted in some type of engine failure or extensive damage to the engine itself. As I told you before the engine itself can run even with the O2 unplugged, which at that point would throw off a code simply because it isn't getting a proper read out, being that the O2 "sensors" are just emission reading devices to gauge the AFR but that's it... I just went over the data print outs with one of the foremans on your vehicle and it clearly states that they are "working as designed."

Understanding that spark plugs typically only cause misfires, but you also stated that at times the engine falls flat as if it's misfiring or possibly feeling like it's running off of only a few cylinders. If the plugs are not detonating properly it can create that type of issue, as I told you to the last time you were here, we would love to service it but there's nothing we can base out repairs off of? We can even call a TS down here from BMWUSA, but chances are without codes what can we do? The TS will probably recommend a carbon clean or fuel injection cleaning..."

Injector cleaning? You guys just replaced the injectors....

"

" Forgot to add that the also replaced the valve cover gasket. I guess I need to check all that myself. There are quite a few connections that could have been messed up. "

"

Nope. Shell only. "

" Nope. No piggyback, no DP fix. Nothing. Just Cobb.

I know. Tune is off. No more pulls for me. "

" Okay, as mentioned in my surging thread, got the car back from the dealer and the issues were not addressed. Did a pull today and finally captured the car sputtering and falling on its face. Right when I get the sputtering the AFR's completely disappear. They aren't logged and there are no values in the CSV file. That length of missing data is precisely the length that the car sputters and when the AFRs come back the car picks up and goes but with some crappy AFRs to follow. WTF is going on...... This is with Cobb Stage 1 Drive map


Attachment 30647 "

" Car has been acting weird ever since it came back from the dealer for new turbos, injectors, HPFP, etc. See THIS THREAD for one issue that has popped up.

The car is currently stock except for Cobb Stage 1 Drive map. In addition to the issue noted above the car seems to be falling on its face after a 2-3 gear shift with moderate to heavy acceleration. Car does not neet to be WOT to get it to happen and it generally happens more often when I shift before redline (car is a 6AT)

When I accelerate in 2nd gear and then shift to 3rd before redline the car just falls flat, stumbles for a bit and then picks up. It feels like a misfire or knock but I don't get a check engine light and there are no codes.


I tried the capture it in a datalog but it of course wasn't as pronounced as a few prior ones.

Datalog #5 is probably the closest but still nothing like when I tried to get on the freeway earlier in the day. (Can't figure out how to post CSV files ) "

" Ever since getting my car back from the dealer for a lot of work (new turbos, water pump, oil filter housing gasket, injectors) I have noticed a surging sensation at light part throttle. It is noticeable as a driver but I doubt a passenger would notice it unless I asked them to pay attention. You can see a very slight change in RPM on the tach but nothing I think would show up on video.

The sensation is only noticeable at about 10% throttle and while maintaing a fairly constant rpm between 1k-2k.

I searched around and some people are suggesting this is a vacuum leak. Would that explain the surging sensation?

The car is 100% stock right now. I looked at the vacuum lines behind the oil filter housing and they don't look great (frayed weave) but no obvious tears in the tubing. I guess it is conceivable one of them was damaged during the warranty repair (specifically the oil filter housing gasket replacement) or during the process of putting the car back to stock.

Is the next step replacing all those vacuum lines? Would the Cobb AP be able to log this issue? "