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Discussion Starter #1
Hi, im having some misfire issues with my 2007 m5 and it also goes into limp mode .i have been working on it the past couple days and I scanned the codes with "bmwhat" and this is what i got: (I CLEARED ALL THE CODES AND DROVE IT AROUND A BIT AND SCANNED IT TO SEE WHAT WAS CURRENTLY WRONG)

Engine / Motor
Fehler: :Engine misfire with emissions deterioration 4 cyl / Lambda adaptation cylinder 8
Code: 2B45

Fehler: :Engine misfire cyl 4 with cut-out / Misfire with cut-out 4 cyl
Code: 2B38

Fehler: :check at lower top / Mass air flow sensor / Security concept manager action
Code: 2B57

Fehler: :Testing of lower stop / check at lower top / Secondary air valve, control / Check to their bottom / Throttle valve actuator, check the lower block / Check to their bottom/throttle flap / Throttle - check lower stop / Security concept manager action
Code: 2796


First thing i did was change the spark plugs, clean the MAF sensor, and brush cleaned all the intake flaps while i was down there. put it back together and same codes still came.

I did more research on the forums and found 2 things that may be causing the issue. first. one of the ionic sensor at the front may be bad so from what i read, switching the 2 ionic sensors places with each other to see if the misfire would change on to the other bank. so i did so, cleared the codes, drove it around again and same codes came, so i ionic sensor are good.

second, i heard the throttle actuators go bad on the s85 engines. so i removed both of them, opened them and noticed some plastic wear down remains all over the inside of the actuator, gears still looked good and everything was catching perfect. so i shot some air in it, cleaned any stuck remains with a tooth pick , put a little grease between the gears to reduce the amount of friction. but overall everything seemed fine in both. put it back together, still same codes. i dont want to just jump into buying new throttle actuators because they are quite pricey. i want to make sure thats the issue before i do that. is there anyway to confirm thats the issue or maybe i should look somewhere else. So now im here asking for help. any suggestions would greatly be appreciated.
 

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I would swap the cyl 4 coil to another cylinder to check the coil. Also I would remove the fuel rail with the injectors still attached and check for a stuck open or leaking fuel injector by turning on the ignition without cranking the engine.
 
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I would check the injector. Especially if you have a O2 sensor error to boot
 

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Discussion Starter #4
I would swap the cyl 4 coil to another cylinder to check the coil. Also I would remove the fuel rail with the injectors still attached and check for a stuck open or leaking fuel injector by turning on the ignition without cranking the engine.
Thank you PRM5 and TROY JEUP, ill get to it and let you know if anything changes. Thanks
 

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Also, check the plug on 4 as well as the coil.

As for the throttle actuator error, replacement gears can be had, but are not guaranteed to solve the problem. If you have let the actuator start up and run the pre-drive check too many times, it can fry a portion of the MOSFETs controlling the internal DC motor. If it's only failed a few times, it may be safe to just buy gears.

Edit: disregard, reread you already changed plugs. Swap coils from 4 to somewhere else.
 

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Discussion Starter #7
Also, check the plug on 4 as well as the coil.

As for the throttle actuator error, replacement gears can be had, but are not guaranteed to solve the problem. If you have let the actuator start up and run the pre-drive check too many times, it can fry a portion of the MOSFETs controlling the internal DC motor. If it's only failed a few times, it may be safe to just buy gears.

Edit: disregard, reread you already changed plugs. Swap coils from 4 to somewhere else.
Hi sorry for the late reply. i somehow bricked my car over the weekend updating the smg software , got that cleared up and working again but Just letting you guys know that when i switched coil 4 with coil 3 the misfire did come up in cylinder 3. ill be going to the dealership tomorrow to pick one up. im hoping this may be the cause to some of the other codes. but if not, and the throttle acutuator does end up at fault. how do i know which one of the 2 is causing the problem. thanks
 

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Hi sorry for the late reply. i somehow bricked my car over the weekend updating the smg software , got that cleared up and working again but Just letting you guys know that when i switched coil 4 with coil 3 the misfire did come up in cylinder 3. ill be going to the dealership tomorrow to pick one up. im hoping this may be the cause to some of the other codes. but if not, and the throttle acutuator does end up at fault. how do i know which one of the 2 is causing the problem. thanks
I was having a misfire on cyl 8 2 weeks before the worst happened, and mine did the SAME exact thing as yours! Limp mode plus increased emissions, a half check engine light, a rattling noise right between the driver side vanos solenoid and the block near the coils. It had half the power as normal BEFORE it officially dropped to the 4000 rpm limit. I took it to NAPA for a check engine light test since I don’t have one of the personal devices yet. They told me bank 1 sensor 3 (o2 sensor) was completely dead. No sign of any activity unfortunately. Having said before I only had a misfire on cyl 8 and no o2 sensor malfunction readings, I’m guessing cyl 8 is a coil or spark plug problem of course; but now that my o2 sensor took a doo doo on me, all cylinders except 2 were misfiring. I’ve been getting a devilish in fact disturbing metallic rubbing/rattling noise I can only hear when I’m behind the wheel between 1 and 3 mph. We may have the same problem in common. Just remember I said that the check engine light hadn’t given me a warning of a failing sensor at all until it died completely. Getting that fixed before any more driving. I have the 2010 e60. Hope this gave you a somewhat insight, if not, a little knowledge for future reference
 

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Hi sorry for the late reply. i somehow bricked my car over the weekend updating the smg software , got that cleared up and working again but Just letting you guys know that when i switched coil 4 with coil 3 the misfire did come up in cylinder 3. ill be going to the dealership tomorrow to pick one up. im hoping this may be the cause to some of the other codes. but if not, and the throttle acutuator does end up at fault. how do i know which one of the 2 is causing the problem. thanks
You will usually know by the codes being thrown, but it sounds like your issue is just a misfire?


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