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2A8C 2A8D codes car won’t accept throttle

615 Views 27 Replies 3 Participants Last post by  HerbP
Really just looking for some assistance or pointers, posted in e60 section but haven’t received any help due to a lack of n62 owners I suppose so I’ll try my luck here.
2007 550i (yes I know not a 6 series)

The car continuously pops 2A8C and 2A8D will only sometimes throw the exhaust cam crank tooth offset error sometimes only on bank 2 sometimes on both banks. I have swapped vanos solenoids and also replaced them I have also swapped and replaced cam sensors still no luck car will start and idle decently for maybe 10 seconds then just falls on it’s face. Does not accept throttle for the most part and on the rare occasion that it does it will backfire through the intake sometimes cylinders will also knock sometimes when it runs extremely rough. The cat on passenger side has gotten red hot a few times (LHD car) I bought the timing tool set and checked that out but it is 100% in time on both banks. So at this rate I’m stumped. Any help is highly appreciated at this point. Car has 167k miles on it. I’ve ordered a new vacuum pump as well old one is leaking.

Could this potentially be a fried DME?
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If the engine is running, the DME is ok. You need to reset the adaptations on the Vanos solenoids, since they have been removed/replaced. The solenoids are calibration for only that position, & will not work properly until the adaptations are reset. What diagnostic tools do you have to reset the adaptations, as this must be done.
I have a launch x431 scanner capable of doing that (which I have) but I also have ISTA+ and I did the CBS oil impaired reset but I only helped for maybe 10 seconds then the car just craters again. Unless there is another process to do that I’m missing? Thanks for the response either way.
If the engine is running, the DME is ok. You need to reset the adaptations on the Vanos solenoids, since they have been removed/replaced. The solenoids are calibration for only that position, & will not work properly until the adaptations are reset. What diagnostic tools do you have to reset the adaptations, as this must be done.
If you have ISTA, you can do all of the needed diagnostics. I am not sure of why you are doing an oil reset, but that want help. Go to the vehicle management/service functions/power train/engine control me9/adjustment/delete adaptions/engine adaptations values. You will know if the problem is fixed as soon as you do this.
Maybe check in the trunk for the cable that connects beyond the spare tire well for a corroded connection... It will have a black or white plastic cover connected to the big red power cables.
Unfortunately this doesn’t resolve the issue it still doesn’t want to take throttle and the rare occasions that it does it will backfire through the intake and rev to 3k with throttle then pretty much go back to idling rough or just dying out. Could it potentially be a clogged CAT? Eccentric shaft sensor? What really bothers me is the obvious engine misfiring but no misfire codes are stored at all. I have 4 new VANOS solenoids coming tomorrow I’ll update how that goes. Should I just get new plugs and coils? I have pulled the plugs and inspected them and to be honest they don’t quite look right. It’s hard to explain I’ll post a few pictures of them in the daylight if it will help.
If you have ISTA, you can do all of the needed diagnostics. I am not sure of why you are doing an oil reset, but that want help. Go to the vehicle management/service functions/power train/engine control me9/adjustment/delete adaptions/engine adaptations values. You will know if the problem is fixed as soon as you do this.
Ah never mind the plugs now just look really rich. Before they didn’t quite look like they were burning anything
Try unplugging the MAF sensor, to see if this will settle the idle down. If this works, it is a default mapping, to limp the car home. At that point I would be testing each Vanos solenoid plug, to make sure it is getting the proper voltage. With one side to ground, you should read 2.84 vdc, & the other side should read 12 vdc. If any one of the Vanos solenoids is not working or seated properly, it will take the complete Vanos system down. If any of the solenoids are not fully seated, the timing is way out of wack. The camshaft sensors, along with the Eccentric shaft sensors can also do this. There is a test in the Service functions menu under one of the DMW I think, that will test the Vanos system is working properly. I don't know what kind of solenoids you purchased, but I hope they are not a cheap set of solenoids, or they might not even work. Either Pierburg or Siemens, I would not even use them. Did you tap the solenoids in all of the way, as sometimes they do not fully seat. At this point the oil bypasses the solenoid, causing the timing to be way off. Check everything out, & give me an update.
Unburnt fuel.
Ah never mind the plugs now just look really rich. Before they didn’t quite look like they were burning anything
Yep it is definitely running quite rich. I’ll be finishing up a truck today for a client so I’ll post later on today when I get back to the bmw and run the diagnostics you’ve listed. Much appreciated either way! Will probably get back to you in the next 10-12 hours.
Unburnt fuel.
Ok this might be dumb but I think the eccentric shaft sensors are bringing the system down. I have noticed that with them plugged in the vanos adaptation values don’t change, but when I unplug both of them the vanos will try to change adaptation values. I have checked the vanos connections and they are fully seated I pushed them in with a pry bar to add some force very gently. MAF plugged or unplugged doesn’t change anything.
Sorry if my eccentric shaft sensor idea is dumb. This is my first N62 I have more experience with N54 and N52.
Unburnt fuel.
If you have a copy of INPA, it might be best to go there and run the engine value. With the analog readings you will have a baseline to see what might be the problem. This will show all of the Vanos sensors & readings, along with the O2 sensors & Maf. When running the values for the MAF, the AC must be off, or the readings will be out of limit, Screenshot the pages, & then we can really see what is going on. The readings below are good, so you can use them as a reference.

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Will do I just charged my laptop so I’ll try that now. I know the bank 1 pre cat 02 sensor is toast from the converter getting red hot though so that reading will be out the window until I get the replacement.
If you have a copy of INPA, it might be best to go there and run the engine value. With the analog readings you will have a baseline to see what might be the problem. This will show all of the Vanos sensors & readings, along with the O2 sensors & Maf. When running the values for the MAF, the AC must be off, or the readings will be out of limit, Screenshot the pages, & then we can really see what is going on. The readings below are good, so you can use them as a reference.

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I have also noticed the temperature readings from the radiator sensor and the engine sensor are drastically different. Radiator reads 79 Fahrenheit and engine reads 191 Fahrenheit. I have a brand new thermostat to put in but just figured I would mention this as well.
these are the values i managed to obtain, it barely wants to idle for more than 5-10 seconds as well.
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The adaptations on Bank 2 camshaft are way off, so I would suggest resetting the adaptations & see what happens. The MAF sensor reading is also out of limit, & the AC needs to be off when this data is collected. Sometimes it take several tries to get the AC to stay off, to get this reading. Since you have had the valve covers off, was anything else done to the motor? Did you replace the valve cover gaskets while the valve covers were off?
I haven’t replaced them yet but I do have some on the way already knew that was a must. Think it might have a huge vacuum leak there? As far as motor work I’m not really sure. I wouldn’t doubt the chain has been replaced it looked pretty new and shiny. I’ll reset them again and try to double check the ac is off. Will keep you updated.
Again huge thanks for taking the time and patience to help me troubleshoot it is much appreciated!!
The adaptations on Bank 2 camshaft are way off, so I would suggest resetting the adaptations & see what happens. The MAF sensor reading is also out of limit, & the AC needs to be off when this data is collected. Sometimes it take several tries to get the AC to stay off, to get this reading. Since you have had the valve covers off, was anything else done to the motor? Did you replace the valve cover gaskets while the valve covers were off?
I use FCPEuro or RM Euro to get my parts. RM Euro drop ships from its warehouses around the country, so I can get most parts the next day, since their warehouse is only 140 miles from me. FCP Euro does give lifetime warranty, but their shipping times are much longer, since everything goes from their location. It depends on how fast I need the parts, depending where I order them from. Both sites will save you lots of money.
Yep I generally go with FCPEuro for my BMW parts wasn’t aware of RM Euro I’ll have to check them out I have gaskets on order from FCP so I’ll replace em when they come in. Just not sure that will fix my issue as it did the same stuff it’s doing now prior to removing the valve covers.
I use FCPEuro or RM Euro to get my parts. RM Euro drop ships from its warehouses around the country, so I can get most parts the next day, since their warehouse is only 140 miles from me. FCP Euro does give lifetime warranty, but their shipping times are much longer, since everything goes from their location. It depends on how fast I need the parts, depending where I order them from. Both sites will save you lots of money.
I would suggest changing the upper timing cover gaskets while changing the VC gaskets. Also change the Eccentric Shaft seals, as they are known leakers. There are some DIY's for the valve cover gaskets in the DIY section if you need them, along with the timing cover gaskets.
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