#8 Misfire Madness

[glenwyatt]

Very long story leading up to buying a 2005 X5 N62 with a CEL on...no point in going there.

So here's what I've got:

1) codes 29CC and 29D4
2) has a mis at any temperature- operating and when cold
3) can unplug a cam sensor an cause it to go into open loops an the mis is neglegable

What I've discovered and done:

1)simple stuff to start with- swapped coils and eventually replaced #8 with a new one
2) replaced plugs, swapped injectors several times.
3)compression test comparing #7(205psi) and #8(200psi)
4) leak down test barely any leak on #8 ~2%
5)looked at the CCV diaphragms- both look new
6)looked for vacuum leak using smoke/pressure in the intake - none
7) looked for vacuum leak using propane and watching O2 values- nothing changes
8) pulled bank 2 valve cover and checked valvetronic system - all leavers date stamped 2014 and valve seal appear to have been replaced and are all class 3
9) swapped levers from 8 to 5 to see mis would move - still on 8
10) checked all hydraulic ball pivots under rockers- all within .1 mm if each other
11) checked timing exhaust timing was slightly out jig sat up 1mm on side closets to exhaust manifold when at TDC but rotate the motor 180 and it was perfect. Intake cam was fine since I got to set it. In GT1 and INPA timing values between bank 1 and bank 2 look to be within 1 degree or less so I didn't move the exhaust cam
12) earased stored adaptation values and did a RAM backup/reset - no change
13) valve cover gaskets are basically new so I just revealed the areas which need silicon....

Basically, I've run out of ideas except to send my DME out for testing and/or repairs.

I should also mention that I had it at a BMW Indy who put 10 hours into diagnosing and couldn't come to any conclusions. He only charged me 2 hours.

What are your thoughts??????

[upallnight]

Hopefully if someone replaced a cam sensor they got the right sensor for the side that they were working on. The cam sensors are NOT interchangeable from one side to the other.

[glenwyatt]

Three of the sensors are the same but the intake cam sensor on the drivers side (bank 2) is not interchangeable but I've confirmed that this is correct. If I unplug that sensor the code comes up as an intake sensor on bank 2 problem. That is a good point though, I've read this mistake before. So since I posted the original post I've pulled the intake manifold off and replaced the gaskets with no change. I think I'm going to dive into the ignition wiring next.