Talibmohamid

I have a 2007 BMW 525XI.....I just crossed over 100K and knew it was time for the service. I figured I could handle it so I changed spark plugs and done the other things that come with the service minus the diff fluid and trans fluid Swap/

What I noticed after the spark plug change was that my car wasnt idleing as smooth as it was before.....I took it to a shop and the tech (a friend of mine) went back over everyting I had done and couldn't figure out any obvious mistakes.

1. He said it could be a bad ignition coil......he said they moved them around and ordered 2 brand new ones from the Bimmer dealership......the symtoms were still there....roungh idle even when they changed them.
2. They checked to make sure there wasn't anything going on with the coils firing the plugs......he said all of the coils were firing / working after troubleshooting and swaping.
3. He then removed what I think in said was the injectors rack......think he swaped those around. Still same not smooth idle...... I always notice at Initial pull off there is somewhat of a studder sometimes....very slight but I can notice it....It doesnt do it everytime but its there. Idle not as smooth as before.
4. I forgot to mention that he called me into the garage and showed me what I think he refered to as ((Smooth Running test)) I believe, he was looked at some software that was relaying realtime how things were firing and the number were bouncing around on all 6 cylinders but on Cylinder 2 and 6 there were noticeable offsets..I think all of them except 2/6 were really close during idling....I can't remember those numbers but I know they stood out so he new it was something going on with cylinder/ 2 & 6.
5. He told me that the cylinders were really soft meatal and said something/some dubre could have fallen down in the cylinder head thats really small or whatever and be on the lifters? He said if it was something big down there it would be obvious and very noticeable. Then he walked me deeper in the garage and showed me a cylinder head that (had been destroyed due to something falling down in there). IT WAS REALLY BAD....I WAS LIKE OMG!!!
6. He said it could be tiny pieces of dirt and things that fell down there when i took the old ones out.
7. So far, the coils have been checked and there fine, the injectors have been checked there fine, the plugs have been checked / swaped and the symtoms dont leave cyliner 2 and 6 and all of the vehichles adaptations have been reset.
8. I'm still getting the rough idle and I forgot he did the BG 44K service on the car for deposits and I think injectors and other things.
9. I forgot to mention that he said the vehicle computer is correcting for the missfires or whatever as best as possible......so the engine light doesn't come on. He was talking to me about head remanufacturing and said that is expensive and he doesn't think that needs to be done yet. Told me to run a few of those Engine Depoist cleaners such as the 44K and possible CFOAM and give it time to maybe work its way out....Said he would love to take my money to remove the head but didn't think that was the case :-).
10. He mentioned it could be a bad Cam or a bad/stuck lifter and to take my time and we would eventually figure out what was going on. If anyone of you master 5 Series guys can give me some pointers or tests or ANYTHING....it would be greatly appreciated. He has been basicly doing alot of this for free because he said he wants to know personally whats going on....

11. Guys is there anything Im overlooking??????
12. My Car NGKS.....I didn't spend the money to get the exact OEM plugs....I got the NGK that was the exact same minus the BMW branding on the actual cermaic part.... http://www.ecstuning.com/BMW-E60-525...ion/ES1884278/

HE SAID IF ANYONE IN HERE has anything thing I could tell him....for me 2 let him know what you guys say....

HELP!!!! THIS CRAP IS GETTING ON MY NERVES!!!!! I KNOW I DON"T have a M5 but I like when my little cruiser is idling so smooth I don't know that its on and not sputtering at all!!!! THANKS GUYS....PLEASE GIVE ME INPUT!!! FEEDBACK!! Stuff I could maybe try... IM GOING CRAZY OVER HERE!!!!!!!!!!!!!!!!!!!!!!

Sublime

My first thought was the adaptive aspects of the ECU needing time to realize you put in new parts. But you mentioned you reset all that. Is there any smoke coming from the rear? Check your oil, is there coolant in there? Aside from universally applicable suggestions I can't imagine how a spark plug change could have this sort of effect unless one or more was either bad, or was damaged to the point where the gap was thrown off. There is always a chance some sort of dirt could have fallen in the cylinder during the removal/replacement but knowing how protected that area is with the coil sitting right on top it feels unlikely to me. If it were me the first thing I would do is to change to a new set of OEM plugs, and if I still had the issue I would put 100 or so miles on the car to see if it settles down. Check the connections to the coils, make sure nothing got in there - sometimes the silicone they protect these connections with mixes with dirt and blocks/reduces conductivity upon reconnection.

Talibmohamid

http://www.ngksparkplugs.com/part_fi...?engineid=2237

these are what I have,,,,, the plugs I have are the exact same plug minus the BMW being printed on the ceramic part......

these.... http://www.ecstuning.com/BMW-E60-525...ion/ES1884278/ are what I orderd....

Veight

Just a thought... Did you by chance remove your oil filler cap and not properly re install it? I did that after an oil change and the car ran like crap. The oil cap looked right but the threads werent properly lined up allowing air to bypass. No error lights went on but the car ran like it was on 7 cylinders.

jay bimma

I have the same NGK #1208 plugs in my 2006 525xi as well. No problems hear with 30,000 miles on the new plugs. Did you by any chance check the gap with the tool before you installed them. You are not supposed to on iridium plugs because the tip is so fine and is very easy to damage.