2010 535i xdrive LCI 75k miles (issue would appreciate help)

[Erik540i]

Hello, just recently bought a 2010 535i xdrive 6 speed manual 75k miles. Was purchased as is of course, and I am having some problems.


So far I have replaced:


6 Coil packs (oem Bosche)
6 Spark plugs (oem Bosche)
MAP Sensor (genuine BMW)


So these codes are what prompted me to start replacing coil packs and plugs:


P0300
P0301
P0303


Symptoms: Car was "shuddering" pretty violently. Took the car to autozone those where the codes pulled. And torque app showed many misfires across the board, but heavily on 1 & 3.


Replaced all coil packs, had to wait for the socket for plugs so could replace those yet.
Pulled codes again and added:
P0420
P0430


Drove the car for a week, and during that time, if I accelerated past 4k rpms i could feel a "wall" break and "Engine Malfunction, Reduced engine power". Also the car would still have some "shudders" while idling and sometimes while driving. Error code P0171 joined the list. (Keep in mind, my little reader is apparently not able to clear BMW cel, but worked fine for other cars, so the original codes have been present the whole time)


Got the socket for the plugs, replaced all 6 plugs. Fired up clean, but after it was warmed up and pushed the 4k rpm, same engine malfunction, less "shudders" but still present.


Next day (today) I purchased the MAP sensor based on some other threads I've read, and past experience with an old e39 540i I owned.


Fired up very clean, felt smooth during initial idle, drove, felt better, "shuddering" was gone from what I could feel, but was leaving my neighborhood so couldn't kick it right up to 4k rpms. Torque app showed only 1 or 2 misfires on various cylinders but not all (some had none). Kicked it up to 4k rpms, same engine malfunction. and "shuddering" returned however misfires stayed 1 or 2 across some cylinders some cylinders had none.


Based on carfax of previous owners, it looks like regular maintenance was done, by BMW. Fuel injectors were replaced by original owner, I assume based on the extended warranty issue.


I am hoping someone might have some insight on what could be the issue. So I can stop throwing money at the wall. Hopefully I have included everything needed to get an idea.


Also if someone knows a place that will clear the codes out for a fresh slate. The autozone by me said their tool cant clear codes. (Chicagoland area if anyone is around and knows places).


Any help would be greatly appreciated, the car drives, but seeing as it has the 4k rpm ceiling it is much less enjoyable.

[Norskie]

Get your own BMW-specific code reader (I use the Carly adapter and app on Android, but there are others) .. you'll pay about $150. The issue isn't just the ability to clear codes, but to see BMW-specific codes. Plus you'll need it for programming the battery, new injectors, etc.

Appropos injectors; there are multiple "versions" which are referred to as "indexes". BMW kept having issues with injector re-designs until Index 12. I believe you can tell the index by the looking at the injector's serial numbers.

In general ... the way to diagnose what's causing a misfire is to move parts around. If you're misfiring on the same cyl's consistently, then swap coil/plug with a cyl which doesn't misfire and see if the misfire moves. If the misfires are all over the place you've got a systemic issue.

The problem you're describing could be a number of things; since it seems RPM-dependent I'd suspect fuel pump, turbo's (wastegates?), VANO. O2 sensors come to mind as well, but I wouldn't expect issues with those to "hit a wall" like you described.

[White94RX]

Good advice from that guy. First order of business is a proper BMW specific scan tool.

Sent from my Pixel XL using Tapatalk

[pbonsalb]

Foxwell NT510 with free bmw specific module when you register it. $155 on amazon.

Will clear much deeper than generic level tool.

Could have bad carbon build up and goo in intake. Very common. Scrape and blast it out after removing intake manifold.