[Game]

Just to update my situation. Got my mosfets and had them soldered on by a local TV repair guy and everything works again. Thanks Roy!

[unrealii]

Originally Posted by Gizm0

Just got the 30BA code today with misfires on five different cylinders... I'm getting 6 new mosfets and hopefully that'll fix the code.

I'm also getting a code for primary O2 sensor on bank one. When I monitor the car at idle using jb4 connected to my laptop, AFR on bank 1 stays at 20 while on bank 2 it is normal (around 14.7)

Note that I just replaced a coil on cylinder 3 this morning because I had a misfire yesterday and it happened to be a bad coil.

I was running e60 mix, FBO with jb4 & e85 flash when the misfire on cyl 3 happened. After replacing the coil, car ran great! I did a log on map 4, all looked good, did a log on map 1, looked good to then a log on map 2 and that's when the DME went bad...

I also had to baby the car for about a mile, at 15mph, all downhill/flat road keeping low rpm so I could park it in a safe place... I hope that didn't make things worse.

I thought 08's and later had MSD81?

[Gizm0]

Originally Posted by unrealii

I thought 08's and later had MSD81?

Mine is a February 08 build and they switched to MSD81 in March 2008 I believe...

[J. Dub]

What a great thread. Thanks for all the support from everyone in here. Mine has not gone south yet, but when/if it does, I will link back to this thread.

[Sherbakoff]

Hi guys!
Do I understand correct that transistors must be unsoldered from the inside? Seems that MOSFET is soldered via several points as it shown on this photo

[HouseN54]

Originally Posted by Sherbakoff

Hi guys!
Do I understand correct that transistors must be unsoldered from the inside? Seems that MOSFET is soldered via several points as it shown on this photo

It's a surface mount, you need a hot air gun to properly remove them unless you are very skilled with a normal Iron.

[Sherbakoff]

I have a hot air gun but seems that it's too big 4 such little transistor, but I'll try nevertheless. May be u know what temperature I'd try?

It must be heated from the top, right?

[CTDrifter]

Giving this a shot this week.

Good tutorial
https://www.youtube.com/watch?v=9D0oTGeheBA

[HouseN54]

Originally Posted by Sherbakoff

I have a hot air gun but seems that it's too big 4 such little transistor, but I'll try nevertheless. May be u know what temperature I'd try?

It must be heated from the top, right?

Yeah that's huge haha you can put couple layers of tin foil over the board and cut a hole like OP did. You remove from the top is correct.

[nemo07]

Recently my N54 had similar issues. Was going WOT and then the car threw codes. I remember a few misfire codes (cyl 6,2,3) but not a 30bb code. Car was shaking rough and a cloud of smoke coming from the exhaust. Got home and checked the valve cover, which had oil all over it. Spark plug 6 had a pool of oil and oil deposits around. Changed the valve cover and same problem. Here's what I did:

- changed valve cover
- started car, misfire 6 after 8-10 seconds
- changed plugs, same issue (all plugs had oil on them)
- swapped coil, same issue (misfire 6)
- swapped inj 6 with 1 , same issue (misfire 6)
- had someone test out the MOSFETs chip on the DME and they said they're all working

Any ideas? I'm stuck

Thanks,

[nemo07]

Bump!

[HouseN54]

Does it smoke still? Oil all over plug? Or oil on valve cover? How many miles, mods, fuel etc

[nemo07]

Originally Posted by HouseN54

Does it smoke still? Oil all over plug? Or oil on valve cover? How many miles, mods, fuel etc

Doesn't smoke anymore when the car starts. Since changing the valve cover, no oil on the cover.

When removed the valve cover, there was a pool of oil in where the spark plug sits on #6. After changing all 6 plugs, I still get a misfire code. I took out plug 6 and noticed oil on the end. When I clean it and put it back, the car starts a bit better but eventually misfires again.

Car has about 156,000 km. FBO+meth

[HouseN54]

Originally Posted by nemo07

Doesn't smoke anymore when the car starts. Since changing the valve cover, no oil on the cover.

When removed the valve cover, there was a pool of oil in where the spark plug sits on #6. After changing all 6 plugs, I still get a misfire code. I took out plug 6 and noticed oil on the end. When I clean it and put it back, the car starts a bit better but eventually misfires again.

Car has about 156,000 km. FBO+meth

Need to get a scope down in to the cylinder and see if your rings are shot.

[nemo07]

I'm gonna do a compression test tonight and see

Thanks!

[Gizm0]

I need some advice here... I had all 6 mosfets replaced by a guy who has done dozens of these repairs before, and kept getting a misfire on cylinder 5. I replaced all the coils and plugs and also replaced cylinder 5 injector, and somehow kept getting a E34 code (injection valve cylinder 5, input signal).

Somehow he messed up one of the solders. The input signal pin on mosfet #5 isn't soldered to the board properly and not making contact.

I used a multi meter to check continuity and mosfets 1,2,3,4,6 are all fine. Mosfet 5 isn't and that's why I keep getting the misfire.

Look at this picture below, the left leg on the mosfet is the one that isn't soldered properly. I hope that can be easily repaired and that the circuit isn't fried. Thoughts?

[Gizm0]

Originally Posted by Gizm0

I need some advice here... I had all 6 mosfets replaced by a guy who has done dozens of these repairs before, and kept getting a misfire on cylinder 5. I replaced all the coils and plugs and also replaced cylinder 5 injector, and somehow kept getting a E34 code (injection valve cylinder 5, input signal).

Somehow he messed up one of the solders. The input signal pin on mosfet #5 isn't soldered to the board properly and not making contact.

I used a multi meter to check continuity and mosfets 1,2,3,4,6 are all fine. Mosfet 5 isn't and that's why I keep getting the misfire.

Look at this picture below, the left leg on the mosfet is the one that isn't soldered properly. I hope that can be easily repaired and that the circuit isn't fried. Thoughts?

Update on this. I had the mosfet #5 replaced, the foot solder was done right this time and the car is back on the road

[BMSE92_Harry]

Mine just took a dump today... 30ba
surprisingly, some common issue with others:
1. 08 335i- but with an early built 07 DME
2. JB4 running on MAP 5
3. Cylinder 2,3 misfire

Sent it to a guy to replace ALL mosfet. Hopefully it will be okay. I have extra coils at home, gonna swap out 2 and 3 coil pack too.

The guy that is fixing it mentioned that he has only seen this problem on 07 DME, hasnt seen one on a 08 or above DME.
He said it's not tune related, seen it on stock car also.
He also said it is most likely heat related.

[HouseN54]

Originally Posted by Harrychiu012

Mine just took a dump today... 30ba
surprisingly, some common issue with others:
1. 08 335i- but with an early built 07 DME
2. JB4 running on MAP 5
3. Cylinder 2,3 misfire

Sent it to a guy to replace ALL mosfet. Hopefully it will be okay. I have extra coils at home, gonna swap out 2 and 3 coil pack too.

The guy that is fixing it mentioned that he has only seen this problem on 07 DME, hasnt seen one on a 08 or above DME.
He said it's not tune related, seen it on stock car also.
He also said it is most likely heat related.

I would definitely agree with him. Anyone who seems to have this problem usually happens after they been cruising for a bit then decided to have a little fun.

[BMSE92_Harry]

Apparently the guy that fixed it said he only seen on 07 built DME. My car is 08 but with an 07 DME. 😫

[BMSE92_Harry]

If anyone needs their DME fix with 30ba or 30bb I can get u guys in touch with a guy here.

[TGNY 335]

Just had this happen to our shop car for bank 1 last night while doing some pulls and logging on a new Flash.

Ordered 6x MOSFET's with PN: FDB14N30TM from Digikey

Due to the holiday they won't be here until Friday. So hopefully we should be back up before the weekend. Hopefully no injectors were taken out with it. New plugs should be here from Burger anyday now. Going to pull the DME tonight and check the MOSFET's and see which one(s) are bad and pull them.

Will update after the repair. Thanks OP (Roy) for this post. Helped out a lot of people.