Vanos - Beginner Questions

[artyM3]

1) Assuming one has a cam alignment bridge and 2 cam alignment pins, why not deploy the bridge with pins inserted into the cams at all times to make sure the cams do not move during the "Vanos Rattle Procedure?" In my reading and watching videos, it seems people take off the bridge and pins only to eventually deploy it again to make sure the cams didn't move. Why? Why not keep it on for the duration of the procedure?

2) Near the end of the "Vanos Rattle Procedure" the instructions state to hand tighten the 2 side bolts on the intake and exhaust sprocket hub only to loosen it again by a quarter turn. What's the reason for doing this?

Thanks for the wealth of information you folks provide through this website!

[karter16]

Re question 1: as part of the procedure you reassemble, then rotate the crankshaft (2 revolutions) and then check that timing has not changed. You can't rotate the crankshaft with the timing bridge and pins in place, hence the need to remove and put back. Is that what you're meaning?


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[artyM3]

Re question 1: as part of the procedure you reassemble, then rotate the crankshaft (2 revolutions) and then check that timing has not changed. You can't rotate the crankshaft with the timing bridge and pins in place, hence the need to remove and put back. Is that what you're meaning?


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Hi, thanks for the response. I'm referring to this video: https://youtu.be/iJRW3BN7NxI?t=1408

The guy inserted the splines back into the Vanos, and he is getting ready to attach the Vanos with the inserted splines back onto the engine. But before he does so, he rechecks his timing with his alignment tools. I just wonder why remove the alignment tools in the first place? I do understand the alignment tool needs to be taken off near the end of the procedure to check for correct timing.

Also, in the next video, part 5, https://www.youtube.com/watch?v=kbX1vfki75g, someone comments: "Btw, you’re making this procedure way, way more complicated than it should be. The ideal, most efficient and easiest procedure is to lock the valve train using the cam locking tool. It locks the cams in time to the crank. Then and only the you can remove the VANOS unit and all 12 bolts without all the fuss of having to crank the engine over manually to tighten the cam bolts. All that is done with the VANOS removed."

Is this even possible? The commenter is implying all 6 cam hub bolts can be tightened down BEFORE the Vanos is even attached if the alignment tools are deployed for the duration of the procedure (up until having to remove the tool to check for correct timing).