Despite having a new fuel pump and some other parts (which helped it run smoother on power) my R56 with N14 engine still has a rough idle. That is not to say I get rev fluctuations, only that the engine vibrates more than I think it should giving slight hickups here and there. Better when warm but never 100% gone. It bugs me!
After reading about Vanos problems and finding a description that matches my symptoms I changed the Vanos solenoid to no effect. Now I want to check engine timing / chain.
Today I put the cams in upright position
(TDC, or it could be crank at 180°) and placed a ruler on each of the the square sections
where the locking tool usually goes. I took a photo with camera on a static tripod so I can compare intake and exhaust angles. I seem to have about 2.9° difference.
See photo. I'm unsure if this is advance or retard?
Anyway, I wanted to confirm that this is not normal, is it? The resting position should have both cams with the square sections exactly aligned, correct?
Just counted the Vanos gear to have 40 teeth, so 9°/tooth. It's not slipped a tooth. Simply a worn chain or lack of tension?
I also checked the Vanos seals that feed oil from cam to Vanos. I read they are rubber on some BMWs and can wear out but mine seem to be steel.
Also I put a spanner on the intake cam and found I was able to move it slightly against the spring of the Vanos gear. It wasn't 'easy' but it was possible with one hand. Video below. Is this normal? I read somewhere it should not be possible to rotate the cam... but the Vanos is a sprung gear.
Vanos cam spring: