Hi Eveyone,

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.

Insight appreciated!

Vanos cam spring:

 

We see the timing off cause all kinds of issues so it's not uncommon to find.
I just install the timing kit and reset the timing if I feel the timing may be an issue.
https://www.waymotorworks.com/timing...7-r58-r60.html

But if going that far if you haven't done it go ahead and do the timing chain kit as they do stretch over time
https://www.waymotorworks.com/timing...-cooper-s.html

 

Did you also lock the crackshaft?

 

No I didn't, so it's possible both cams are off time with the crank. I don't have a timing kit or I'd have reset it already. It can't be too bad though the car has happily done a few thousand miles like this and will rev to the limit. It's just rough at low RPM and possibly down on power (can only compare with memories of my previous R53).

However at 49K I think maybe it's time for a new chain kit. Does seem kinda early though, isn't recommended interval 70K or something?

 

personally not sure about recommended interval, but, you could stick an allen key in the whole just to verify.

it is also possible that spark plugs or coils are at the end of their life.

with about 50k, it could be possible you have carbon build up.

or might be a hairline crack in the pcv vent pipe.

one time i bought a mini that had 180 deg timing off. it ran fine, kind of, but it wasnt as strong.

 

Thanks. I thought the same things, so I already replaced the PCV hose (added a catch can) as well as a new valve cover. I also did new spark plugs, 4 new injectors (got a good price), a new HPFP and a new vanos solenoid. I checked the vacuum pump for binding and I've manually cleaned the intake valves (probably not as good as a walnut blast but they ain't terrible). It's not all a waste of cash as it drives far better now than it did when I bought it, but that low RPM roughness is still there and after spending so much money and time I can't tolerate it!

I didn't change the coils but my guess is that tired coils would be worse at higher RPM than low.

I had no idea an engine could run 180 deg out of phase! Amazing!

 

Here's a screenshot from newTIS.info showing the "vanos seals". One time when I was in there, one of them was broken. Dealer had only plastic replacements, apparently the steel versions are discontinued. Anyhow, I highly recommend you use this site for torque specs / instructions / etc anytime you take it apart. The instructions are very similar, if not exactly the same as the dealer techs use.

 

sorry for reviving an old thread
but have you found solution by any chance? i believe i’ve got similar problem with idle

 

I didn't see any mention of ignition coils...made a big difference for me. Look at Facet, similar to NGK.