[derrick603]

2007 335i
MHD stage 1
97k miles
auto

Last week, I changed my spark plugs and the cylinder 6 coil to fix a cylinder 6 misfire (plugs already had 10k, so I changed them all since I was already in there). Since then, I've had some stuttering in 6th gear when accelerating moderately from 2k RPM. I can reproduce this consistently, and after doing so about 20 times, I still have not gotten a CEL or a code in the scanner.

I tried autologging and didn't see anything funny, but I'm not an expert at reading MHD logs. Do my logs show anything? Are there other parameters I should be logging? The car seems to run fine outside of this situation (also happens in 5th at 2k, but less often).

https://drive.google.com/open?id=0Bz...G5RcDBiRmNNWjg

[335e92tx]

Reset all adapts first (prob not throttle) and then do a manual of steady state speed (static throttle position) with at least 10 seconds of data . AND upload to datazap.me

Will try to have a look. No real definitives... Usually related to load req exceeding load actual at around 10-12 percent throttle based on what I have seen. Why is unclear.

[WatchWolf34]

Did you torque the plugs to 18?

[TemjinX2]

are you using the same brand coils for cylinder 6 as the rest of your cylinders? Germany cars are picky and don't like it when you mix and match brands.

You try swapping out coil in cylinder 6 with a different one?

You check the spark plug in cylinder 6, make sure nothing is damaged or chipped?

[Lite203]

Your logs look fine.

I was having this same issue on the stock tune and it turned out being carbon build up. These motors are so dang touchy and mine were horrid. I just bought my car 15k ago and its at 95k, I'm almost positive it's never been cleaned. After cleaning manually with a gun cleaning kit and lots of brake cleaner, I reset the adaptations and took it for a drive. It was still missing for around the first hour of cruising around, then it just stopped. Car is running beautifully on MHD Stage 1 FMIC.

Id recommend doing what Temjin said, if none of that fixes it, It's possibly an injector, but I would try cleaning for carbon build up, especially if you've never done it. It's recommended around every 30k on regular pump gas. They get BAD quick.

[derrick603]

Originally Posted by 335e92tx

Reset all adapts first (prob not throttle) and then do a manual of steady state speed (static throttle position) with at least 10 seconds of data . AND upload to datazap.me

Will try to have a look. No real definitives... Usually related to load req exceeding load actual at around 10-12 percent throttle based on what I have seen. Why is unclear.

I'll reset the adaptations and see how it goes. The car seems to be fine at low throttle in 6th, but not at 50%.

[derrick603]

Originally Posted by WatchWolf34

Did you torque the plugs to 18?

I didn't have a good torque wrench handy, but they should be close. Some of the plugs felt a little sticky when screwing them in, so it's possible they're torqued correctly but not in all the way.

[derrick603]

Originally Posted by TemjinX2

are you using the same brand coils for cylinder 6 as the rest of your cylinders? Germany cars are picky and don't like it when you mix and match brands.

I'm using these specifically:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Originally Posted by TemjinX2

You try swapping out coil in cylinder 6 with a different one?

I didn't bother switching them around, I just replaced it with a new one. To me, it wasn't worth the time to mess around with it when the original part has almost 100k on it and the replacement part is cheap.

Originally Posted by TemjinX2

You check the spark plug in cylinder 6, make sure nothing is damaged or chipped?

The old plug looked fine but I replaced it anyway. I had a CEL for cylinder 6 before replacing it and the coil, but with the new stutters, I'm not getting a CEL, and they're happening at a different time from before.

[derrick603]

Originally Posted by Lite203

Id recommend doing what Temjin said, if none of that fixes it, It's possibly an injector, but I would try cleaning for carbon build up, especially if you've never done it. It's recommended around every 30k on regular pump gas. They get BAD quick.

I had a walnut blasting done about 35k miles ago.

[MyNameIsNotSure]

I think I have a similar, or even the same problem as you. Check out my thread on it. Did you happen to figure out what was wrong? Interestingly enough I have the same Amazon coils as you and after looking into it, they might be the culprit due to counterfeit/poor amazon quality. I'm about to order some Eldor coils and I'll reply back if those change anything.

[Miller335]

Originally Posted by derrick603

I had a walnut blasting done about 35k miles ago.

Not saying it's your issue but valves should be cleaned every 30-40k miles.
I did mine at 33k (Have 52k now) a they were gunked up.

[derrick603]

Originally Posted by MyNameIsNotSure

I think I have a similar, or even the same problem as you. Check out my thread on it. Did you happen to figure out what was wrong? Interestingly enough I have the same Amazon coils as you and after looking into it, they might be the culprit due to counterfeit/poor amazon quality. I'm about to order some Eldor coils and I'll reply back if those change anything.

I haven't been driving the car as much lately, so I'm still waiting for the ECU to tell me which cylinder is having an issue. My guess is a bad spark plug since I didn't have this problem until I replaced the plugs a few weeks ago.