You are currently viewing our forum as a Guest.
By registering not only can you take part in the forum, it will also remove most of the adverts.

Intake balance shaft sprocket buggered

Discussion in 'Cam Chains' started by cheeseza, April 15, 2018.

  1. Hi all

    Got the dreaded rattle. Which would normally go away but a couple of weeks ago it became permanent. So parked the car up and waited to get everything ready.

    Started doing the job and when I went to remove the right hand guide of the timing chain, loosed the bottom bolt and it just fell out in pieces.

    Looking through the hole in the head, no top bolt. I am assuming that one of the previous owners had the chains changed and then the bolt was missed. Also the oil sprayer was damaged.

    This seems to have buggered the intake balance shaft sprocket. I can't see the timing mark on it.
    Is there a way to still do the balance timing, or do I have to replace that sprocket?

    How hard is it to do with the engine in?

    Anyone have a part code?

    Any special way to get this done, or just put a pin in the hole to lock it and then replace it? Should I do both or should the other 1 still be ok? I can still see the mark.

    And the more pertinent question, do I need to remove the sump to get the other pieces out or should they not pose any risk between the oil pickup and the oil filter. Haven't drained the oil yet. So will see what comes out. Hopefully the chains mangled them to small enough pieces to either come out of the sump or be caught in the filter.

    Attached Files:

  2. I would drop the sump , clean the pick up pipe out , clean the sump , if the bolt is snapped in the head , might be better removing the head , mine was snapped but came out , but did have head off , you get the balance shaft bearings in the chain kit which I would get , genuine kits the best kits too get ,,
  3. you can clearly see the notch on the sprockets, above the arrow, that is the alignment pin
  4. so it's pointing down in your photo
  5. It's prudent to install a new balance chain kit whilst doing the timing chain kit.
    If you haven't purchase the kits already then have a look at the following links:
    Timing Chain Kit here - which is the latest genuine GM kit (includes Z20NET tensioner, updated oil nozzle, timing cover gasket and crankshaft oil seal).
    Balance Chain Kit here - again genuine GM kit which includes both the balance shaft sprockets.

    Individual part numbers for the sprockets and bolts are:
    Sprocket,Engine Vibration Damper Balance Unit Shaft,RH (Intake Green) - 55354438
    Sprocket,Engine Vibration Damper Balance Unit Shaft,LH (Exhaust White) - 55354439
    Screw,HEX.HD.,M10 X 25,Sprocket to Engine Vibration Damper Balance Unit Shaft - 11588737 (x2)

    The easiest way to remove the sprocket bolts is to rap the old chain around the sprocket and hold it with mole grips while undoing the bolts. Vauxhall recommend using new balance shaft sprocket bolts (listed above) which are torqued to 8 Nm / 6 lbf ft, then angle-tighten a further 30°.

    You will have to remove the sump to clear any broken pieces of the front timing chain guide otherwise they will block the oil pickup pipe which could cause engine damage. Use instant gasket to seal the sump, but give it a few hours to set before filling with oil.

    Hope that helps. :)
    #5 KevinH, April 15, 2018
    Last edited: April 15, 2018
  6. So first order of business is to check if the bolt had broken off or never put back in.

    I did think that, but didn't want to risk it incase that was a coincidence.

    Do you reckon that sprocket could still be ok?

    Have you recently posted these items for sale on eBay?I ordered the 2 kits on the 5th of April and don't believe I saw your listings. I would've definitely bought yours as it was from the same supplier and yours has more parts included. The 2 kits I got, while still being genuine GM, did not include the 2 balancer sprockets, the crank seal or the gasket. Can you please advise the part number of the updated Z20NET tensioner to make sure what I have is the latest. If not I will return and buy yours.
  7. Hi Kevin,

    Just did a search in the eBay app and none of your listings come up. I copied the product name up until the > sign. Still nothing.

    The direct link works.

    Not sure if it is just me, but maybe you part isn't live or something on eBay.
  8. These are about the best value genuine GM kits around - they're not my listings.

    The GM part number for the Z20NET timing chain tensioner is 12608580.
    If you buy the balance chain kit from a Vauxhall dealer the balance shaft sprockets are not included and this is why the kits are good value from this supplier.- the sprockets alone are about £60 each from the dealers. :)
  9. The bolt is snapped in the head:mad:

    I wonder if I could get it out with a left hand tap.

    Hopefully it is not torqued too much and breaks tap.

    Any other suggestions/remedies that don't involve removing the head?
  10. I just bought a bolt extractor kit. Wish me luck.
  11. The guide bolt should come out OK - they are all torqued to 10Nm / 7lbf ft (or just pinched up if your torque wrench doesn't go that low). :)
    #11 KevinH, April 16, 2018
    Last edited: April 16, 2018
  12. Thanks KevinH. Let's hope the goodies I bought are up to the task.


    Is it customary for the head to be so gunked up? I change the oil every 6 months or less. Car does very little mileage as it's the wife's car. Would flushing oil give it a decent enough clean or am I asking too much of it?


    Should I be worried about very slight putting on some of the cam lobes?
    #12 cheeseza, April 16, 2018
    Last edited: April 17, 2018
  13. The engine looks rather blackened - have you been using a fully synthetic oil for the oil changes?

    What year is the vehicle and what's the mileage?
  14. I only ever use full synthetic 5w30 oil. Oil changes have been with Shell Engine Oil (Helix Ultra Professional AG Engine Oil - 5W-30 - 5ltr) with 1 change using GM oil from Autovaux.

    2005 model

    101,500 miles.

  15. So, is your engine the Z22YH rather than the Z22SE?
  16. Yes. YH.
  17. In which case the timing chain kit is slightly different to the Z22SE as the YH has a cam sensor on the exhaust camshaft sprocket.

    The Z22YH timing chain kit here

  18. You could try an engine flush at some point - one of the best on the market is Forté Advanced Formula Motor Flush. :)
  19. I've got a can of flushing oil from eurocarparts that is lying around somewhere. Just had a look and the blackness just wipes off.

    Some good news, the broken bolt came out. Now to drop the sump and hopefully that's all.
    • Like Like x 1
  20. Good news about the bolt - magic !!! (y)

    Seems strange that the engine is quite black when you've changed the oil regularly.
    Assume the timing chain kit you bought was for the YH.