Z4 M54 exhaust vanos

[Jamturbo]

Hi,
I have had a prob over the last few months where the idle has been rough. Symptoms are: intermittent rough idle / engine shakes sometime when idle / seems to drive ok when it is going.

I rebuilt the double vanos about 3 years ago. I recently replaced both exhaust and intake solenoids and put new pistons / oil change a week ago. I changed the crankshaft sensor (exhaust).

My diagnostic machine reads ‘stiff exhaust mechanism’.

Any thoughts what might be the problem or what to look at next.
Thanks

[Jamturbo]

Update. Took the car to a BMW specialist. Worst fear diagnosed, vanos unit. This time I wasn’t up to sorting it myself. Anyway, got the car back today after the vanos unit was replaced. Problem sorted and idle is perfect.