View Single Post
      07-31-2019, 06:40 PM   #2
Michael9218
Lieutenant
Michael9218's Avatar
595
Rep
484
Posts

Drives: 2007 Z4 M Coupe
Join Date: Oct 2012
Location: Woodstock, GA

iTrader: (0)

When you timed the cams, how did you make sure the vanos pistons were fully retracted?

The Biesan procedure doesn't mention this, but just pulling on the cams to push the pistons didn't get them all the way in for me. My car ran fine but eventually threw a cam timing code (no limp mode). I cracked it open to check and both were about 6 degrees retarded.

The way it was explained to me is that the pistons have some air pressure in them after you do the full rebuild. One should loosen the piston caps and allow air to escape when you do the initial cam timing. Also us the OEM timing tool. The various cheap ones are sloppy and can also give inaccurate results.
Appreciate 1