Mods Delete

[Liquidsk8s]

Hey guys, first post, naturally it's for an issue haha.

So I've been reading up on the "Engine Malfunction Reduced Power" threads others have made, and mine is a little different/weird.

Car is completely stock, 135i N55 DCT M Sport. Spark plugs changed 500 miles ago (few weeks) to stock plugs/gap. Did oil at the same time (oil level is perfect still). Had a few spirited drives here and there but mostly quick trips to the store. I don't drive a lot since I take the train into the city. Nothing has stood out to me.

Fast forward to today. My wife went to the store, then called me because as she backed out of her parking spot the car shuddered and died, giving the Engine Malfunction warning. Restarted and warning was gone and car drove fine. Later she mentioned shes had a few moments where shes had a delay in power recently. She continues on her errands and come home with no further incidents.

Now I'm jumping into it and trying to recreate the issue. Start it up, no issue, idles fine. After 5min of idle it suddenly shudders and shuts off giving the warning. Threw my scanner on and pulled only one code P10D9 for the fuel rail sensor. No CEL on the dash though. Cleared and restarted to see if it would pop up again. Let it idle for 15min with no more issues. Took it out for a drive and car felt more responsive, WOT with zero issue. Parked and went into the store, came out and started the car......shudder and die. Restart shudder but stayed on this time and then idled normal. Revs fine, no codes thrown. Drove home went WOT once and it was perfect with zero issue.

My first thoughts were HPFP, but everything I've seen on those tends to be with the N54, and are not intermittent and only at idle like mine. They also tend to throw multiple codes not just one. Which makes me think I should start with this as the cheapest starting point since the only CEL was aimed at this. Fuel Pressure Sensor

I don't think it's the plugs since the car drives perfect, WOT no issue, no misfire codes etc. I'll keep you posted on what I find, and any thoughts/advice are much appreciated. First BMW and first electrical gremlin lol.

[dtla1]

I would move this to the General Discussions section since these sub-sections tend to get little traffic these days.

I agree that a HPFP failure would most likely throw a "Pressure too low" code or something like that, don't remember exactly what it says. And HPFP do go bad on the N55, I've replaced mine already.

You are probably on the right track with the fuel pressure sensor. I would buy one of the sensors to be ready, but in the meantime clear the codes and drive it 'till it happens again and pull the codes again to see what comes up.

How many miles on the car, any other mods? Also did your wife happen to fill the car with gas before this started, could be a case of bad gas (fuel, not the other type of bad gas) maybe?

[Liquidsk8s]

Originally Posted by dtla1

I would move this to the General Discussions section since these sub-sections tend to get little traffic these days.

I agree that a HPFP failure would most likely throw a "Pressure too low" code or something like that, don't remember exactly what it says. And HPFP do go bad on the N55, I've replaced mine already.

You are probably on the right track with the fuel pressure sensor. I would buy one of the sensors to be ready, but in the meantime clear the codes and drive it 'till it happens again and pull the codes again to see what comes up.

How many miles on the car, any other mods? Also did your wife happen to fill the car with gas before this started, could be a case of bad gas (fuel, not the other type of bad gas) maybe?

Thanks the tip on moving it to general. Now the question is how to do that haha. Mods?

Car has 56k miles, completely stock. She filled it up recently and I verified she got 93. Possible bad gas (hopefully). I ordered a OBDII scan cable to run logs as well to help pinpoint the issue, arrives tomorrow so I’ll jump in even further.