[ny330xi]

When I drop my car into gear, the idle continues to drop and surge. No issues above idle or in P.

I've logged battery voltage, and though I may get a slow crank when the temp is below zero, the voltage remains near 14v under load. So, I don't think it's a charging system issue.

This issue has been intermittent since the summer, but isn't setting off any codes. And with the cold weather, it's gotten progressively worse.

Is it a bad coil that's not registering a code, MAF, and ideas?



UPDATE

Changed the plugs today, the stumble appears to be gone. Hopefully it stays gone.

[ny330xi]

TTT

Any ideas on how to diagnose this with no codes?

[BavarianMWfan]

I got the same problem but at idle since mine is manual. I have done air filter replacement, vanos cleaning, maf cleaning, used injector cleaner and changed battery (it was due). Only a minor improvement. Which leaves spark plugs and ignition coils. I would do the spark plugs first.

[Kool G Stacks]

I'm having similar problems. Check my post to see if the answers apply to you as well, "on the way to palisades mall"

[ny330xi]

Thanks for the replies.

Today, it got worse. Stumbling at acceleration, not just idle, and then I finally got an SES. Misfire, cylinder 6.

I'm just going to replace all 6 coils and call it a day. I just searching around now for the best price on OEM coils shipped.

[BashShah]

Replace the plugs also.
Look for eBay seller: Germanautosupply.
Best price and all oem.

DN

[ny330xi]

Originally Posted by DarkNemesis

Replace the plugs also.
Look for eBay seller: Germanautosupply.
Best price and all oem.

DN

Looks like I'll need to. Replaced #6 coil, still stumbling. I guess I'm just going to do coils/plugs as soon as I can get them in.

[vapore0n]

You should look into bad injectors.

I had a missfire on cylinder 6. Changed sparks/coils and the problem persisted.
Eventually had to change the injector.
Just saying because I spent around 300 just to replace the coils/plugs, when it really wasnt needed.

[ny330xi]

Originally Posted by vapore0n

You should look into bad injectors.

I had a missfire on cylinder 6. Changed sparks/coils and the problem persisted.
Eventually had to change the injector.
Just saying because I spent around 300 just to replace the coils/plugs, when it really wasnt needed.

No codes?

I think that injectors tend to be an issue on the n54 much more so than the n52. But I'll definitely consider it.

I'm changing out the plugs this week. At $50, it's really no harm no foul.

[Meeni]

Injectors can also cause trouble on the n52 but usually a bottle or two of techtron cleaner fixes it.

[vapore0n]

Originally Posted by ny330xi

No codes?

I think that injectors tend to be an issue on the n54 much more so than the n52. But I'll definitely consider it.

I'm changing out the plugs this week. At $50, it's really no harm no foul.

I had a code for misfire on 6, P0306

[Agentphish]

I've been having rough idle/stumbles at start after the car was driven and sat for a bit but was still warm. No codes.

I left it with the dealer last night hoping they are going to cover under repeat repair within the 2 year repair warranty. They have replaced lifters, all 6 coils, VC/VCG, eccentric shaft sensor and valvetronic gasket within the last 18 months. The plugs were checked and are fine (only have ~18K on them anyway). I checked for vacuum leaks, use Techron every 4 months or so and I cleaned the MAF and VANOS solenoids though neither appeared to be dirty, and have had no change in my symptoms, so I'm just going to let them figure it out...though they've been unsuccessful at doing so in the last 2 appointments.

I hope they actually find something, but if it's not a repair they'll cover I'm not going to pay them to do it.

[Zero_09]

Sounds like the same problem I have. Seems like you replaced everything I thought it was. Eccentric shaft sensor and coils.

I'm getting a misfire on cylinder 6 and 29E0 and 29E1 codes showing as Mixture control.
Tried cleaning the vanos but still the same. When it gets colder the problem is worst. The idling is shaky when my car sits overnight in the cold also.

Keep us posted if the dealer finds the problem.

[ny330xi]

Replaced plug 6 this evening - didn't have time to do the rest. It settled out a lot, but still stumbles intermittently at idle.

I'll replace the rest on Saturday morning when I have some time. I expect that should solve the issue.

[ny330xi]

Changed 1-5 plugs today and torqued 6 to spec - didn't have a wrench on Tue when I changed the plug. The stumble seems to be gone.

As a side note, that #5 plug is a real PIA to get to, btw. I removed the strut bar - not sure how people do it with it in.

[Meeni]

Manual instructs to remove the strut bar.

[vapore0n]

I never removed the strut bar.
Having plenty of extensions and elbow sockets works great.

[nukezero]

Strut bar removal not needed. Get some elbow socket extensions and there is enough room to get it in and out. Go to Harbor Freight. Spend $60 and buy all the extensions, elbows, for 1/2 and 3/8 and you'll use it for life. Get the black oxide impact ones. They are designed for high torque impact wrenches and will not break with your hand torque.

[nesnith]

Was your foot on the brake the whole time when it happened?

[ny330xi]

Originally Posted by nesnith

Was your foot on the brake the whole time when it happened?

No