[Supr3me]

Originally Posted by Alan340

It barely happens under acceleration, but it has happened. And yes, I have removed the JB4 completely and even took it to the dealership but wasn't able to replicate it over there. A mechanic gave me his number and I sent him a video of the boging/misfire or whatever it is problem and said it was normal.

Was your issue just like mine? Did you change the coils?

My issue is primarily on cold start and I would describe it as a "chuffing' sound for a few moments directly after start up.
I was getting the code from cylinder 4, moved that coil to cylinder 3 and now the code has moved to cylinder 3. Replacement coil is on the way.

Without any codes, it's a lot harder for you to diagnose.

[Mr. 340]

Originally Posted by Sµpreme

My issue is primarily on cold start and I would describe it as a "chuffing' sound for a few moments directly after start up.
I was getting the code from cylinder 4, moved that coil to cylinder 3 and now the code has moved to cylinder 3. Replacement coil is on the way.

Without any codes, it's a lot harder for you to diagnose.

Yeah it is a lot harder to diagnose without any codes.

Just uploaded a video so you can see how mine is. Here I am holding the rpms around 1,000 so the problem sounds more pronounced on video.

[Supr3me]

And this is with JB4 completely removed?

What do the misfires under acceleration feel like? Do you feel a stumble?

[Mr. 340]

Originally Posted by Sµpreme

And this is with JB4 completely removed?

What do the misfires under acceleration feel like? Do you feel a stumble?

The JB4 was on but I believe I had it in map 0. I recorded this a month or two ago so don't exactly remember, but it was for sure installed.

Yeah. It just feels like a small hiccup. Again I have only felt it probably twice while actually driving.

[Supr3me]

I would remove the JB4 and confirm that it's definitely still happening, take a more recent video, and then ask the dealership again to try to get to the bottom of it. Ask to work with the tech to recreate the problem for them if you know it only happens under certain conditions.

[Mr. 340]

Originally Posted by Sµpreme

I would remove the JB4 and confirm that it's definitely still happening, take a more recent video, and then ask the dealership again to try to get to the bottom of it. Ask to work with the tech to recreate the problem for them if you know it only happens under certain conditions.

Here are two videos with the JB4 completely removed. Just recorded them.

Second video is engine sound. You can hear small knocking sounds very faintly in the background.

[Mr. 340]

Originally Posted by Sµpreme

I would remove the JB4 and confirm that it's definitely still happening, take a more recent video, and then ask the dealership again to try to get to the bottom of it. Ask to work with the tech to recreate the problem for them if you know it only happens under certain conditions.

I just saw you have a Pure 800 in your 340i. How has it been since you installed it? How many miles have you put on it? Any issues? I am interested because I will do Pure 800 next year.
Thanks!

[Supr3me]

Originally Posted by Alan340

I just saw you have a Pure 800 in your 340i. How has it been since you installed it? How many miles have you put on it? Any issues? I am interested because I will do Pure 800 next year.
Thanks!

Knock on wood it's been good. I'm on my 3rd rev to the base/safety map and the car is really moving
I've had some various issues come up but as far as I can tell, they're mostly of my own making. This cylinder ignition issue is the only thing that I don't think was due to me doing something dumb.

This I will say- with every mod we stray further from God's light lol. The car starts way harder on E85. A full tank of gas is gone in 200 miles. It's no longer the car you bought at the dealership. It's still a daily for me, but it requires a lot more attention.

https://giphy.com/gifs/parks-and-rec...-Xj1GHC7mXPquY

[Mr. 340]

Originally Posted by Sµpreme

Knock on wood it's been good. I'm on my 3rd rev to the base/safety map and the car is really moving
I've had some various issues come up but as far as I can tell, they're mostly of my own making. This cylinder ignition issue is the only thing that I don't think was due to me doing something dumb.

This I will say- with every mod we stray further from God's light lol. The car starts way harder on E85. A full tank of gas is gone in 200 miles. It's no longer the car you bought at the dealership. It's still a daily for me, but it requires a lot more attention.

https://giphy.com/gifs/parks-and-rec...-Xj1GHC7mXPquY

Good to hear man. And yeah of course, every power mod will stress the engine a bit more. We just have to stay on top every other supporting mod to make reliable power.

I don't know if you saw what happened to LJ (No Clutch garage) his Big Boost Stage 4 340i blew up due to inefficient fueling. But I mean, we learn with every mistake.

Thanks for the feedback and help for my engine issue! Appreciate it big time

[Socaln54]

bump

[les anderson]

2016 340i, 40k miles. Was in for a random noise (seat, not mechanical) issue and ended up having valve cover gasket replaced after routine inspection. Supposedly "just" starting to leak. No prior tangible signs that it was an issue however.

Bm3 stg 1 since 37k miles.

[G.Newt]

Originally Posted by les anderson

2016 340i, 40k miles. Was in for a random noise (seat, not mechanical) issue and ended up having valve cover gasket replaced after routine inspection. Supposedly "just" starting to leak. No prior tangible signs that it was an issue however.

Bm3 stg 1 since 37k miles.

Welcome to BMW ownership. I fully expect to have to replace my valve cover and OFHG during ownership at least twice, if not 3 times
Curious to see your work order if you don't mind posting it! How did they find the leak? Thanks.

[StannisBaratheon]

Originally Posted by les anderson

2016 340i, 40k miles. Was in for a random noise (seat, not mechanical) issue and ended up having valve cover gasket replaced after routine inspection. Supposedly "just" starting to leak. No prior tangible signs that it was an issue however.

Bm3 stg 1 since 37k miles.

Was it covered under warranty?

[les anderson]

Originally Posted by G.Newt

Welcome to BMW ownership. I fully expect to have to replace my valve cover and OFHG during ownership at least twice, if not 3 times
Curious to see your work order if you don't mind posting it! How did they find the leak? Thanks.

Yes, replaced under warranty. Again, this was not something I noticed and it was apparently caught early.

[fake_bimmer]

This is my 340i
made in Rosslyn
Power check result by Dynapack shows its max power is 409ps (tcf:1.0)@4th gear.

My modification so far:
ENGINE:
•DME tuned by private tuner in Japan(maybe using ecutech or alientech device)
•TCU remapped by D.I.Y :xHP stage3 v1.7
•akrapovic revolution line exhaust and linkpipe with akrapo sports cat.
•K&N air filter
•OKD ignition coil(multi-spark coil),which is very popular tuning parts in Japan
•CSF heat exchanger (v.1)
•B58TU HPFP

[henry_z4]

Hi Everyone,
last night something happened to my 35.000km M140.
I was escaping form an attempted theft (two cars tried to squeeze me but I managed to escape) and I went uphill close to my neighborhood to leave them behind.
I lost them after a few turns but I kept pushing for a while to be sure to escape them definitely and gain some time to put the car in the garage when at home.
After 60-70 seconds of driving up the hills the car started to heavily whine when I was full gas. I could hear the noise since mid low revs up to high revs.
Noise comes from the front (engine bay). I felt no power loss at all.
Car is stock with just M Diff.
Once at home I couldn't hear the noise anymore and this morning the car felt quite normal.
with the dashcam I recorded a couple of video so you can hear the noise.
Should I be concerned and go to an appointment with service?
Here's the noise:
https://youtu.be/dwPe266iXbA
https://youtu.be/eiXzWeWsDTg

[theone1973]

Originally Posted by henry_z4

Hi Everyone,
last night something happened to my 35.000km M140.
I was escaping form an attempted theft (two cars tried to squeeze me but I managed to escape) and I went uphill close to my neighborhood to leave them behind.
I lost them after a few turns but I kept pushing for a while to be sure to escape them definitely and gain some time to put the car in the garage when at home.
After 60-70 seconds of driving up the hills the car started to heavily whine when I was full gas. I could hear the noise since mid low revs up to high revs.
Noise comes from the front (engine bay). I felt no power loss at all.
Car is stock with just M Diff.
Once at home I couldn't hear the noise anymore and this morning the car felt quite normal.
with the dashcam I recorded a couple of video so you can hear the noise.
Should I be concerned and go to an appointment with service?
Here's the noise:
https://youtu.be/dwPe266iXbA
https://youtu.be/eiXzWeWsDTg

hmm so strange, I can hear the sound but dont know what it is.

What the fu*k is wrong with people. Highjacking cars pure idiots !

[henry_z4]

Originally Posted by theone1973

hmm so strange, I can hear the sound but dont know what it is.

What the fu*k is wrong with people. Highjacking cars pure idiots !

So you have same car. do you have manual or ZF?

[theone1973]

Originally Posted by henry_z4

So you have same car. do you have manual or ZF?

M140 with ZF mate

[alyabiev]

Originally Posted by theone1973

M140 with ZF mate

That's classic ZF whine. Mine does the same thing at trackdays when car is pushed hard without cooldown laps.

[henry_z4]

Originally Posted by alyabiev

That's classic ZF whine. Mine does the same thing at trackdays when car is pushed hard without cooldown laps.

good to know. I had just DKG auto before so I haven't a big experience with ZF.

[G.Newt]

Originally Posted by Sµpreme

Knock on wood it's been good. I'm on my 3rd rev to the base/safety map and the car is really moving
I've had some various issues come up but as far as I can tell, they're mostly of my own making. This cylinder ignition issue is the only thing that I don't think was due to me doing something dumb.

This I will say- with every mod we stray further from God's light lol. The car starts way harder on E85. A full tank of gas is gone in 200 miles. It's no longer the car you bought at the dealership. It's still a daily for me, but it requires a lot more attention.

https://giphy.com/gifs/parks-and-rec...-Xj1GHC7mXPquY

I hollered lmao. Thanks for the laugh.

Regarding your cold starts: I see you're in a colder climate like me. A lot of the N54/N55 boys here running full E85 needed tuning adjustments to be able to start in the winter. I'm only on E30 and noticed a slightly longer start time, nothing that I'm really concerned with though. I know the HPFP upgrades just became available this spring, so wondering if we'll see complaints come up during late Fall/winter.