Timing chain slack

[Icecream]

Thats about how mine looked. Its not going to be completely rigid. All the tensioners were in when you timed it right?
have you gone grey yet?

[stash1]

Have you gotten so far as to see if the VANOS is adapting in the ECU?

[sapote]

So after issues with timing my engine after my Vanos work I've come to the conclusion my problem is likely from the slack in the timing chain.

Here is a video of the slack, just for visual reference:

https://youtube.com/shorts/XacCjaD47Ig

To properly time the engine I must set the crank JUST before TDC, the crank locking pin is unable to be inserted.
If I set my cams up while the crank locking pin is installed the timing bridge does not sit flat, I've tired numerous times and I always end up with a small gap on intake side for both cams, the exhaust cam having the larger gap of about 1mm.

I have heard on the this forum that it might be OK to "cheat" the timing as I am doing, but after talking with a local BMW shop and the main dealer they didn't think that is the greatest idea.

The indie shop recommended replacing the tensioner as maybe the spring isn't 100%.

If I'm over-complicating things, sorry, but I just wanted to get a few more opinions as far "cheating" the timing goes.

Is it bad to cheat? Sure it's bad to cheat in school examine or cheat your friends. But it's OK to cheat the VANOS to make it even more happier and better.

Look, at the end of the day, after verifying by turning the crank 2 or 4 turns and lock the crank at TDC and the cams are timed perfect with the bridge pin, if you don't tell everyone that you cheated, then who cares as long as it's perfectly timed? Why the BMW shop or the dealer need to know how one arrived at such a perfect timing?

I had looked at the video, and it's normal and not chain slack. You can't expect to have the chain stays as a solid piece of metal when pulled. The small error that you saw on the bridge is normal as everything has tolerance and not absolutely precise. Cheat by set the crank a little retard is to compensate for these accumulated tolerance to nullify it and this is perfectly fine. Don't listen to those shop or dealer as they just follow the book but don't care to know of how the whole system works.

[Cubieman]

So after issues with timing my engine after my Vanos work I've come to the conclusion my problem is likely from the slack in the timing chain.

Here is a video of the slack, just for visual reference:

https://youtube.com/shorts/XacCjaD47Ig

To properly time the engine I must set the crank JUST before TDC, the crank locking pin is unable to be inserted.
If I set my cams up while the crank locking pin is installed the timing bridge does not sit flat, I've tired numerous times and I always end up with a small gap on intake side for both cams, the exhaust cam having the larger gap of about 1mm.

I have heard on the this forum that it might be OK to "cheat" the timing as I am doing, but after talking with a local BMW shop and the main dealer they didn't think that is the greatest idea.

The indie shop recommended replacing the tensioner as maybe the spring isn't 100%.

If I'm over-complicating things, sorry, but I just wanted to get a few more opinions as far "cheating" the timing goes.