GO FISHING, use SLABSAUCE Fishing Attractant
Results 1 to 3 of 3

Thread: Timing chain loose?

  1. #1
    Join Date
    Aug 2004
    Location
    Southern New Hampshire
    Posts
    54

    Default Timing chain loose?

    Hi All,

    I have a 1993 525 (Vanos) that has been backfiring on startup and I'm trying to hunt down the problem. You probably saw some discussion on the subject here: http://www.bimmernut.com/forum/showthread.php?t=42567

    I pulled the valve cover off to check the timing and make sure things are lined up as far as valve timing. While turning the engine manually, I found that the exhaust cam starts to move before the intake moves. I would expect both to start moving simultaneously. Has anyone seen this behaviour and is it normal?
    It makes sense to me that if the intake cam is engaged late due to a loose chain, the intake timing is essentially retarded and would keep the intake valve open upon ignition of cylinder.

    Thanks for any input on this.

  2. #2
    Join Date
    Oct 2004
    Location
    Honolulu
    Posts
    3,105

    Default

    Hope you are rotating the crank clock wise....

    Keep in mind that the first few tugs on the crank without the Vanos being pressurized can leave some sloppyness as the un pressurized vanos is rotated and the intake gear is allowed to move a few degrees as the play is taken up.


    Vee ave vays of dealing vid your kind...........

  3. #3
    Join Date
    Jan 2004
    Posts
    4,150

    Default

    Agree with Bob, vanos allows some play in the gear, normal.


Similar Threads

  1. M60 timing chain tensioner help!
    By BillionPa in forum 5 Series BMW
    Replies: 2
    Last Post: 06-24-2006, 07:32 PM
  2. timing chain slap?
    By liquidtiger720 in forum 5 Series BMW
    Replies: 10
    Last Post: 12-13-2004, 01:30 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •