[blakeelkin]

Hey everybody, I just changed all the coils and plugs on my n55 due to misfiring. 2 done by a shop under extended warranty because of codes coming up and the other 4 done by me because car kept misfiring and they quoted $1,200 since warranty wouldn't cover them without codes. Now I'm still having misfiring problems (especially when giving applying throttle while shifted into higher gears) and occasional stumbles while idling (especially during cold starts).
My warranty is about to run out in 200 miles (I'm at 73.3k) and I want to make sure it isn't some major problem. Any ideas on what I could test out? Maybe checking the pressure coming out of the HPFP? Any help is greatly appreciated, thanks!

[harkes]

Originally Posted by blakeelkin

Hey everybody, I just changed all the coils and plugs on my n55 due to misfiring. 2 done by a shop under extended warranty because of codes coming up and the other 4 done by me because car kept misfiring and they quoted $1,200 since warranty wouldn't cover them without codes. Now I'm still having misfiring problems (especially when giving applying throttle while shifted into higher gears) and occasional stumbles while idling (especially during cold starts).
My warranty is about to run out in 200 miles (I'm at 73.3k) and I want to make sure it isn't some major problem. Any ideas on what I could test out? Maybe checking the pressure coming out of the HPFP? Any help is greatly appreciated, thanks!

Could also be coils. 6 pulgs are ~100usd and they take max 1h to change so I hope you didn't pay 1200 for that. Logging the engine sound like a plan. HPFP, AFR, IGN

[Chriske92]

Originally Posted by blakeelkin

Hey everybody, I just changed all the coils and plugs on my n55 due to misfiring. 2 done by a shop under extended warranty because of codes coming up and the other 4 done by me because car kept misfiring and they quoted $1,200 since warranty wouldn't cover them without codes. Now I'm still having misfiring problems (especially when giving applying throttle while shifted into higher gears) and occasional stumbles while idling (especially during cold starts).
My warranty is about to run out in 200 miles (I'm at 73.3k) and I want to make sure it isn't some major problem. Any ideas on what I could test out? Maybe checking the pressure coming out of the HPFP? Any help is greatly appreciated, thanks!

My misfire was turbo related. They installed a new turbo under warranty

[blakeelkin]

Originally Posted by harkes

Could also be coils. 6 pulgs are ~100usd and they take max 1h to change so I hope you didn't pay 1200 for that. Logging the engine sound like a plan. HPFP, AFR, IGN

Changed the coils with the plugs, and definitely wouldn't pay that hahaha. I let them change the two plugs and coils that came up on the codes because it was covered under my extended warranty. I'll make sure to get all of that checked out, thanks! Any other tests I should have them run before my warranty ends in 200 miles?

[blakeelkin]

Originally Posted by Chriske92

My misfire was turbo related. They installed a new turbo under warranty

Haha was just looking up if people got their turbo switched out because of that garage wastegate rattle. Any other symptoms that accompanied the turbo issue? Did you have a similar misfire around medium throttle while shifted into a higher gear? My car completely stumbles two or three times when giving it gas at highway speeds

[13blk335ix]

mine stumbles too. got new spark plugs gapped at .018 was better for a bit but it's back now at highway speeds. need help

[blakeelkin]

Originally Posted by 13blk335ix

mine stumbles too. got new spark plugs gapped at .018 was better for a bit but it's back now at highway speeds. need help

Are you using the NGK plugs?

[XutvJet]

Are these all OEM plugs and coils?

Any engine modifications?

[blakeelkin]

Originally Posted by XutvJet

Are these all OEM plugs and coils?

Any engine modifications?

No mods, stock plugs and coils (Bosch and Delphi)

[cfm56d7b]

blakeelkin, by any chance were you or the first shop able to identify any stored codes? When the engine misfires, its a fairly serious matter and codes are stored immediately.

Four systems may not perform correctly when the engine misfires:

- Delivery of air
- Delivery of fuel
- Ignition
- Wiring / how electrical signals are carried

Spark and coils are the first item to check. There might be an air leak somewhere. At 73K miles, it's worthwhile to check the OEM charge pipe if it's still present.

The next step would be to check fuel injectors. Bad injector can literally flood the cylinder.

[13blk335ix]

Originally Posted by blakeelkin

Are you using the NGK plugs?

yes

[blakeelkin]

Originally Posted by cfm56d7b

blakeelkin, by any chance were you or the first shop able to identify any stored codes? When the engine misfires, its a fairly serious matter and codes are stored immediately.

Four systems may not perform correctly when the engine misfires:

- Delivery of air
- Delivery of fuel
- Ignition
- Wiring / how electrical signals are carried

Spark and coils are the first item to check. There might be an air leak somewhere. At 73K miles, it's worthwhile to check the OEM charge pipe if it's still present.

The next step would be to check fuel injectors. Bad injector can literally flood the cylinder.

Appreciate the help a bunch! Going to switch out the injectors and see if that fixes it. I'll check the valve cover for any leaks and the charge pipe while I'm at it. Think if that doesn't fix it then I'll move onto replacing the low pressure and high pressure fuel pumps since supposedly they might be recalled since I have a 2013. Here's to hoping my extended warranty will cover that!!

[blakeelkin]

Originally Posted by 13blk335ix

yes

I had found a good N54 sticky thread talking about all the main reasons the engine might be misfiring and all applies very well to the N55 aside from the intake valve carbon buildup.
Check it out here: https://www.e90post.com/forums/showthread.php?t=631829

Going to change injectors and let you know if that alleviates the issue.

edit: also have you already changed coils? If you haven't that's most likely issue after plugs. Easy change too. Here's the same product as the BMW plugs made by Delphi just half the price and missing the BMW branding:
https://www.fcpeuro.com/products/bmw...-12138616153-1

[13blk335ix]

thanks will change coils next

[Zyler]

So were any codes thrown and if so which ones? I had a misfire in cylinder 1 and it threw a code immediately. The misfire was due to a slightly over tightened spark plug.

[13blk335ix]

no codes thrown. I have bm3 stage 1 and it's been happening ever since I installed it

[13blk335ix]

I have a 2013 f30 n55 335ix 6mt. ER chargepipe, afe drop in air filter, wagner catless downpipe, bm3 stage 1 93 tune. NGK plugs gapped at .018.

[akgambino]

Originally Posted by 13blk335ix

I have a 2013 f30 n55 335ix 6mt. ER chargepipe, afe drop in air filter, wagner catless downpipe, bm3 stage 1 93 tune. NGK plugs gapped at .018.

Why did u gap them to 0.018 and are only running stage 1 tune? That tight of gap is reccomended only for high boost applications.

[Rebound]

Originally Posted by 13blk335ix

no codes thrown. I have bm3 stage 1 and it's been happening ever since I installed it

So... you'd want to disconnect the BM3 to see if the misfires stop, right? I don't think you need to remove it altogether, just unplug its connections to see if the problem goes away.

[blakeelkin]

Originally Posted by 13blk335ix

thanks will change coils next

When I was changing coils I figured i had to take off the strut brace because the back two were clearly blocked but it was literally impossible to find the e-whatever socket to take it off (plus needing to buy new fasteners).
I figured out that you can simply unscrew the plastic cover over the back two coils (3 10mm on each end) and then wiggle it around to the right side of the engine under the strut brace. This gave me more than enough room to remove plugs and coils.

[blakeelkin]

Originally Posted by blakeelkin

Hey everybody, I just changed all the coils and plugs on my n55 due to misfiring. 2 done by a shop under extended warranty because of codes coming up and the other 4 done by me because car kept misfiring and they quoted $1,200 since warranty wouldn't cover them without codes. Now I'm still having misfiring problems (especially when giving applying throttle while shifted into higher gears) and occasional stumbles while idling (especially during cold starts).
My warranty is about to run out in 200 miles (I'm at 73.3k) and I want to make sure it isn't some major problem. Any ideas on what I could test out? Maybe checking the pressure coming out of the HPFP? Any help is greatly appreciated, thanks!

Took car to Mike's Bimmer here in SFL and they're doing some logging/checking injectors. Should have the verdict tomorrow.

[blakeelkin]

Originally Posted by 13blk335ix

I have a 2013 f30 n55 335ix 6mt. ER chargepipe, afe drop in air filter, wagner catless downpipe, bm3 stage 1 93 tune. NGK plugs gapped at .018.

When you're changing the coils you might want to take a plug out and check it. As akgambino mentioned .018 might be too small of a gap for stage 1. Make sure it's burning clean, and if so then drive on! If not I'd consider possibly regapping them or even buying some of the OE Bosch plugs until you move up to a higher tune. Here's where I got mine, 10 bucks ea.

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