Rough Running 335i JB4

dylanAr10 · 11-26-2016, 05:41 PM

OK so heres my story, I recently replaced a few injectors due to small shakes this initially solved my issue but only temporarily. I still got little shakes but a lot less frequently and less violent and no SES so I chalked up to that's just the way the engine runs. So recently when I was on the way to work I got on it and the car spit out a half engine light. So I figured this weekend I'll hookup INPA and check to see if the other injectors may be starting to fail. I however did not realize that INPA does not work with the JB4 (I kept getting a bunch of prompts and whenever I'd click yes on INPA my blinker of all things would flash) so I decided to close out INPA and try and take her out on a drive and see If I could replicate the half engine light. As soon as I got on it that car SES & Half engine light came on and I had very little power. So I went and parked turned the car off to try and remedy the situation but no luck now the car idles so roughly the entire car shakes. Can INPA corrupt the ECU? Or is that a coincidence and is it likely the HPFP? Also would I be covered by BMW if it was the HPFP (under 120k) any help is greatly apperciated! Thanks in advanced everyone!

Also to note there was a whining that started before this that I didn't recognize.

zooch7 · 11-26-2016, 07:13 PM

Did you read JB4s info about things that need updated on your car before or during install? Spark plugs, coil packs, etc. How old are they? I didnt see the info provided above.

dylanAr10 · 11-26-2016, 07:39 PM

Coils & plugs were replaced by the dealer (less than a year ago) I have pulled them in the past few months and can confirm they are solid.

dylanAr10 · 11-27-2016, 05:49 PM

Thinking its quite possibly the DME (The Mosfet(s) that control the injector(s)) Does anyone know how to confirm this?

dylanAr10 · 11-27-2016, 07:07 PM

Update: Found a video here pulled the DME and tested the mosfets looks like I am ordering some new mosfets. Good thing I already have a hot air rework station & Iron lol.

dylanAr10 · 12-03-2016, 07:25 PM

Update part two: Installed the new mosfet on Thursday and reinstalled the DME. Much alike the guy in the video it was my cylinder 5 that blew. One thing to note the mosfets the guy suggest are not 100% the same as the ones on there originally but I can personally confirm they work. If memory serves max voltage handling was different amoung a few other minor things but over all they are nearly identical. Also I couldn't even find anyone selling the original mosfets. Anyway I tried to start my car but sadly the battery was dead as a door nail and I had work so today I got it charged and put it back in. I started the car and again she was running rough but the power wasn't being stifled like before. So I hooked up INPA and low and behold cylinder 5 was running like shit. Swapped the coilpacks from 4 & 5 and it followed to cylinder 4. So I imagine once I get my new coilpack I'll be back in business. I suggest to anyone with the intent of doing this that you buy 12 or more mosfets. I only ended up using 1 but I now I have 11 in case this happens again.

11-26-2016, 05:41 PM	#1
dylanAr10 Private 15 Rep 81 Posts Drives: E92 M3 Join Date: Oct 2014 Location: Superior iTrader: (0)	Rough Running 335i JB4 OK so heres my story, I recently replaced a few injectors due to small shakes this initially solved my issue but only temporarily. I still got little shakes but a lot less frequently and less violent and no SES so I chalked up to that's just the way the engine runs. So recently when I was on the way to work I got on it and the car spit out a half engine light. So I figured this weekend I'll hookup INPA and check to see if the other injectors may be starting to fail. I however did not realize that INPA does not work with the JB4 (I kept getting a bunch of prompts and whenever I'd click yes on INPA my blinker of all things would flash) so I decided to close out INPA and try and take her out on a drive and see If I could replicate the half engine light. As soon as I got on it that car SES & Half engine light came on and I had very little power. So I went and parked turned the car off to try and remedy the situation but no luck now the car idles so roughly the entire car shakes. Can INPA corrupt the ECU? Or is that a coincidence and is it likely the HPFP? Also would I be covered by BMW if it was the HPFP (under 120k) any help is greatly apperciated! Thanks in advanced everyone! Also to note there was a whining that started before this that I didn't recognize. Last edited by dylanAr10; 11-27-2016 at 05:45 PM..
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11-26-2016, 07:13 PM	#2
zooch7 Private First Class 22 Rep 100 Posts Drives: 08 335i Join Date: Jun 2016 Location: Eugene, OR iTrader: (0)	Did you read JB4s info about things that need updated on your car before or during install? Spark plugs, coil packs, etc. How old are they? I didnt see the info provided above.
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11-26-2016, 07:39 PM	#3
dylanAr10 Private 15 Rep 81 Posts Drives: E92 M3 Join Date: Oct 2014 Location: Superior iTrader: (0)	Coils & plugs were replaced by the dealer (less than a year ago) I have pulled them in the past few months and can confirm they are solid.
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11-27-2016, 05:49 PM	#4
dylanAr10 Private 15 Rep 81 Posts Drives: E92 M3 Join Date: Oct 2014 Location: Superior iTrader: (0)	Thinking its quite possibly the DME (The Mosfet(s) that control the injector(s)) Does anyone know how to confirm this?
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11-27-2016, 07:07 PM	#5
dylanAr10 Private 15 Rep 81 Posts Drives: E92 M3 Join Date: Oct 2014 Location: Superior iTrader: (0)	Update: Found a video here pulled the DME and tested the mosfets looks like I am ordering some new mosfets. Good thing I already have a hot air rework station & Iron lol.
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12-03-2016, 07:25 PM	#6
dylanAr10 Private 15 Rep 81 Posts Drives: E92 M3 Join Date: Oct 2014 Location: Superior iTrader: (0)	Update part two: Installed the new mosfet on Thursday and reinstalled the DME. Much alike the guy in the video it was my cylinder 5 that blew. One thing to note the mosfets the guy suggest are not 100% the same as the ones on there originally but I can personally confirm they work. If memory serves max voltage handling was different amoung a few other minor things but over all they are nearly identical. Also I couldn't even find anyone selling the original mosfets. Anyway I tried to start my car but sadly the battery was dead as a door nail and I had work so today I got it charged and put it back in. I started the car and again she was running rough but the power wasn't being stifled like before. So I hooked up INPA and low and behold cylinder 5 was running like shit. Swapped the coilpacks from 4 & 5 and it followed to cylinder 4. So I imagine once I get my new coilpack I'll be back in business. I suggest to anyone with the intent of doing this that you buy 12 or more mosfets. I only ended up using 1 but I now I have 11 in case this happens again.
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