Ok, so here is the background and already completed troubleshooting that I have done for my wife's 2006 BMW 325i.
First signs of trouble began with the following codes:
1. P0015 "B" Camshaft Position- Timing Over Retarded (Bank 1)
2. P1447 Diagnostic Module Tank Leakage (DMTL) Too High During Switching
3. P1449 Diagnostic Module Tank Leakage (DMTL) Too High
4. P0301 Cyclinder 1 Misfire Detected
Immediately went to the #4 problem to start working things instead of the others to start with what I thought would be the easier problems.
- Started with the coils, swapping Cyclinder 1 and 2 coils and the code didn't change off of P0301, so changed the spark plug. Additionally, pulled off and checked fuel injectors and looked for any exterior issues. Was not able to check interior mechanisms.
- After changing the Cyclinder 1 spark plug, all of the mentioned initial codes disappeared, BUT gained the code P0302, so decided to simply replace all 6 spark plugs and see if the codes went away. After replacing all the spark plugs, now getting the codes P0300, P0301 and P0302, so having multiple misfires now.
At this point, I have read over multiple posts that multiple things could be the culprit now. Instead of starting to buy parts one by one of all the possible scenarios, I was wondering how to test one of the original code issues P0015 "B" Camshaft Position- Timing Over Retarded (Bank 1) since I have read this could directly affect misfire issues. Additionally, I have read that intake issues could also cause multiple misfire issues, while fuel issues could do that same thing.
Ok, these are generic codes rather than BMW specific codes. If you can get a tool like the Foxwell, or setup some PC software with a cable, you'll be able to pull the BMW codes. You'll get far more informatiom from the BMW codes. I would tackle the camshaft timing issue first, then look at the misfires. BTW, the DMTL issues are REALLY common on all of the e90s, it's a $70 module that you can change out in half an hour.
The Camshaft position issue has to do with the VANOS system. Read SI B11 02 08 to get more info on that issue. Basically the car uses oil pressure to advance camshaft timing. Check that your oil filter and stand are in good shape, and make sure you are running the correct weight oil. Try cleaning and swapping your VANOS solenoids to see if the fault follows. If you continue to experience issues, you might need a camshaft bearing ledge.
The only codes currently reporting are the P0300, P0301 and P0302. I understand these are not the BMW specific codes, and as such I have ordered a new reader so hopefully will have that within the week.
As stated the camshaft error no longer is showing in the current errors codes, only the P0300, P0301 and P0302 codes. Understanding the start point, applying the spark plug changes, you really think it goes back to the Camshaft issue? I did go thru and check the oil filter and stand and everything looked solid.
Are the plugs properly gapped?
Oxygen sensors or vacuum leaks can sometimes cause misfires without throwing codes.
The spark plugs came in at .044 pre-gapped and ready to throw right in. I was wondering about the O2 Sensor, but I presumed that would throw a code. Additionally, I looked around the engine compartment area, and didn't find any obvious vacuum leak, but honestly I don't have a diagram of all the vacuum lines at the moment to trace everything to check.
Additionally, so I currently have 6 codes, and may have saw something that confused me in another forum post. I still don't have the Foxwell reader, but it's enroute as I live in Hawaii so it'll be a week before I get BMW specific codes, BUT my current reader gives me the 6 codes with P0300 Freeze Frame and P0300 Pending, then the same matching set for P0301 and P0302..... Does this mean that I just need to run it a bit and the system will adjust off these codes? Someone said in another forum post that if you have the codes in a pending status, the computer system after running for a bit adjusts and these codes will go away.....
Thoughts?
The vehicle at this point seems to run just fine when at speed, but idle is rough. Seeing above, any thoughts to next step? My new reader shipped, but wife is getting impatient to have her car back lol
Being a little more specific, runs fine once at speed say above third gear speeds. Otherwise lots of power loss early on.
Last edited by travispagan; 01-17-2018 at 02:51 AM.
My post may totally be misleading, as I have not researched the appropriate spark plug gap for your car, however .44 just seems high to me.
The N54 (not your motor) by my research is below. After changing mine from .04x (new out of the box...) to .027, my former 335xi coupe's little hits, particularly when cold, went away immediately.
Stock: Gap is .022 inch
JB4 (@ +100HP, 1 Stage cooler Plug): Gap is .029
When you get the new code reader it will be easier to understand and see what codes are there. I had driveability problems and at one time 4-5 different codes earlier this winter and changed all 6 plugs to E3 plugs (I like them). Ran much better but #3 cylinder misfire came and so I moved that coil to #1. Ran perfectly for a day then #1 cylinder misfire came up so I knew that coil was no good. Eventually put in a new coil and all has been good since. There is a chance you have more than one bad coil travispagan. Good luck and keep posting.
Bookmarks