Hello Everyone,
I have this issue just came out today after i installed the new MAF sensor. The rpm acted like crazy and i am not sure what is the reason for that ? I had some alternator failure as the dealer told me and i noticed that. However, when i plug the old MAF the rpm will not act crazy but it will go under the normal rpm idling and then will go up suddenly !! i have attached the video related to the 2 issues ! hope to find a solution !

I am waiting my alternator to be delivered tomw and i have also ordered Crank position sensor + a belt kit so with pulleys and everything !
https://vid.me/delete/13vn5j4zs7vkk8sg0gcs88swc

https://vid.me/delete/9h1ysk2fno4ckc0o0k4kgsoo0

 

Any idea ?

 

It seems the MAF is not your problem. Have you taken the IAC out to check to make sure it is working properly. Take it out and move it in a twisting motion. You should hear it move back and forth. Clean it out with some brake cleaner and install. You should be good. How does the car act without the MAF plugged in? If you are having the same issue without the MAF then its not the issue.

 

Thank you seanjordan20 for the replay. In fact, no i didn't check the IAC i just cleaned the throttle body yesterday. However, do you have any video that will help me to locate the IAC for my 2008 550i v8 so i can try and do it in my garage ! I will try to plug the old one and see what will happen and i will try to unplug it and try without having the MAF plugged in !

Will update when anything changes ! keep my fingers crossed

 

I want to add that i got 2 trouble codes before i changed anything from my OBD II which are
P2188: system too rich at idle bank 1
P2190: system too rich at idle bank 2
I thought that might help you guys to find the solution quick !

 

UPDATE: I tried the old MAF and the idle just raised as before (sudden) then back to normal. However, with the new MAF it will keep going up and down forever !! when i unplug the sensor connector everything looks smooth ? I am not sure if the problem with the new MAF or not ? I also noticed the car is going to die with the idle and then it gets back up normally ! the thing i've noticed is the alternator is coming to it's end because every electric thing in the car is flickring and that was obvious + a smell of electric and noise from it ! I will get my belts and the new alternator today and i hope that will fix the problem !

In addition to that I got a bunch of new codes
P0100 - Mass or volume air flow circuit
P113B - it says this fault code is not found in the database
P0113 - intake air temperature sensor 1 circuit high
I am not sure what are these for ? hope you guys know !!

 

P0100 came from unplugging the MAF
P2188/P2190 comes from air getting in by either a missing MAF (if you didn't have it in while the car was running) or air leak at the air filter.

 

The first thing I would do is handle your power issues then go from there. Bad alternators can cause a lot of issues that are not there.

 

Thanks for you help

 

I just got my new alternator today. I will change it with changing the drive belts and the pulleys and hope everything will be okay !!