Nach Zylinderkopf Wechsel, Nockenwellen Position unklar | Posts 16+

The problem is as follows:
Once the NW wheel is removed, two elongated holes become visible. The question I have is, through which of these holes should the pin for securing it be inserted?

Unfortunately, the reference manual only mentions that the NW rad position indicator must point upwards.

The hole for fixing should be approximately at the 8 o'clock position, which means the camshaft needs to be rotated in order to be able to fix it.
According to my understanding, you shouldn't just rotate the camshaft alone, as the valves could potentially collide with the pistons.
Am I completely mistaken here? ...

You're not completely wrong.
The hub has a protruding feature (not visible, located under the disc), and the camshaft has a corresponding groove. This must be aligned to the 12 o'clock position, which will place the camshaft in the top dead center (TDC) position for cylinder 1 (this should be confirmed by someone who has worked on the hub before!). The slots will then be at approximately 8 o'clock and 4 o'clock. The slot at 8 o'clock is used for locking.
With the timing belt already removed, the crankshaft is rotated 90 degrees from the top dead center (TDC) position of cylinder 1. This allows the camshafts to be freely rotated to the desired position and secured.
So far, so good, but I'm now asking about a VCDS account or a support key.
hg
Herbert.

Thank you very much!
That sounds great so far.

"VCDS is available, but my colleague is handling that; he's familiar with it."
Before starting, I'm going to connect the laptop and see if it displays anything.
As far as I know, with "newer" vehicles, various things also need to be reset or reconfigured after a major repair or modification.
I still need to do some more research about the CAAC in general.

Okay, so, rotate the KW (keyway) 90 degrees (clockwise?).
Then, position the camshafts and secure them in place.
Then, turn the crankshaft back (counterclockwise?).
According to the reference guide, I believe you should always turn it in the direction of the clock hands, but I need to double-check that.
Otherwise, the motor would have to be rotated another 270 degrees in order to be properly secured again.

Imagine the operating principle of a crankshaft with connecting rods and pistons. It doesn't matter if you rotate the shaft alone, either clockwise or counterclockwise, from the top dead center (TDC) of cylinder 1; all the pistons are away from TDC. Of course, the rotation back to TDC (cylinder 1) must be done in the opposite direction, otherwise the pistons that are 180 degrees out of phase will reach TDC and collide with open valves.
When using a timing belt, things are a bit different. The camshaft rotates along with it, and you want to secure it. In that case, you naturally use the tensioning side specified by the manufacturer, so you turn it clockwise. Incidentally, the central bolt is loaded in the direction of tightening.
What I don't like is that you're starting this type of repair relatively recently (I've also started before), but you're actually having someone else do it, who clearly doesn't know what they're doing either. The repair guide and the colleague's VCDS are from somewhere else. And now we're supposed to help this "expert combination," funded by customers, from a forum. The quality here doesn't just appear; it's because the owner has maintained it at his own expense for many years.
hg
Herbert.

Hello Herbert,
I understand your comment.
Not everything went according to plan with the action, and it also took much longer than expected.
My father and a friend did most of the work, but then my father didn't have the time to finish it. I had to get involved and check everything to make sure it was correct, and in the end, it wasn't.
So, on the one hand, it's good that I double-checked everything before starting, but on the other hand, it's a shame I wasn't involved from the beginning.
Furthermore, I mainly work on older vehicles, where almost everything is self-explanatory, and you don't need VCDS or similar tools.

PS: I started 8 years ago, so I wouldn't consider myself a beginner anymore, but rather an amateur .