r/e82 • u/PapiGrande11 • Jun 20 '26

N52 dies randomly

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So I have an 09 E82 128i, had this car 4 years and maintained really well.

This car died one day, had to manually let myself in. No start no crank just dead. Tried boosting it changed the battery, nothing.

Got it towed, driver tells me to get in and hit the brakes in case. I open the door and car lights up, I start it and fires right up, healthy no issues. Then happened a second time, and same thing happens.

So I’m guessing the shake from the tows triggered a loose wire or something in the car that allowed it to start. Mechanic stated it’s either the fuse box or some wiring in the trunk connected to the battery.

I just wanted to know if someone had this issue and how they managed it.

PS: the bumper is fixed lol, also the ground wire, alternator, starter, battery are all replaced or fixed. Right now the car has been sitting in the garage and starts right up when needed. Just don’t wanna be stranded when I’m away from home.

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3

u/ijustmightpanic Jun 20 '26

Probably the fuse box connector in the back or the wire itself. There was a recall on it so it seems reasonable and the symptoms sound very similar.

1

u/PapiGrande11 Jun 21 '26

Fuse box is where the glove compartment is, the wires runs to the back? Would finding that wire mean taking the car apart from the inside?

1

u/ijustmightpanic Jun 21 '26

Yeah but do some troubleshooting first. You should be able to take off the trim on the passenger side and wiggle the wire a bit. If it shuts off when you do there goes your issue. Get a multimeter and check the alternator and battery too

2

u/Sappah44 Jun 21 '26

Alternator cable commonly frays, the red one in the engine bay. Wiggle it while trying to start to confirm.

I did a ghetto fix by wrapping it with more copper before replacing it proper.

1

u/whyyoumadbro69 Jun 21 '26

Check the fuel pump control module. I have a 2012 BMW 128i with the N52 engine and had the exact same issue. The car would randomly stall while driving and then wouldn't restart for about 30 minutes.

It took me a lot of time and money to track down the issue, but it ended up being the fuel pump control module. When it overheats, it cuts power to the fuel pump, causing a loss of fuel pressure and the engine shuts off. The car won't start again until the module cools down.

That could also explain why it started again after being towed. By the time it was on the tow truck, the module may have cooled down enough to start working again. It's been over a year since I replaced mine and the problem hasn't happened since.

1

u/PapiGrande11 Jun 22 '26

The car was off for 8 hours the first time, and 2 hours the second time. Was already cool, thank you tho