Checking for timing jump
06-26-2011, 11:11 AM
#19
Chronic Tool Dropper
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Charley--
Maybe GB and the other more serious engine gurus will jump in on this. My amateur knowledge has me wondering how the heck that cam jumped that much and nothing else seems to be disturbed. It would take some serious available travel in the tensioner to let the belt ride up for that many teeth on the cam gear. It would seem to me that the slack from that would cause the belt to jump the passenger-side cam first. Per chance, did you check the belt tension as it sits now? That loose, at least on mine, would have the dash warning lit up well before there was that much travel in the tensioner.
Just my rambling thoughts...
Maybe GB and the other more serious engine gurus will jump in on this. My amateur knowledge has me wondering how the heck that cam jumped that much and nothing else seems to be disturbed. It would take some serious available travel in the tensioner to let the belt ride up for that many teeth on the cam gear. It would seem to me that the slack from that would cause the belt to jump the passenger-side cam first. Per chance, did you check the belt tension as it sits now? That loose, at least on mine, would have the dash warning lit up well before there was that much travel in the tensioner.
Just my rambling thoughts...
06-26-2011, 11:44 AM
#20
Team Owner
check the tension before removing the belt,
this isnt normal so something has failed for the belt to jump.
usually the teeth will, come off the belt.
this isnt normal so something has failed for the belt to jump.
usually the teeth will, come off the belt.
06-26-2011, 03:28 PM
#21
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The tension is definitely on the light side but I don't have the experience to interpret degree vs impact.
There are no belt shavings anywhere but there is some damage to the leading edge of the belt here and there. Again, I don't know if it's enough to account for anything. I imagine the belt damage is the result of a worn cam gear or two.
There are no belt shavings anywhere but there is some damage to the leading edge of the belt here and there. Again, I don't know if it's enough to account for anything. I imagine the belt damage is the result of a worn cam gear or two.
06-26-2011, 03:39 PM
#22
Team Owner
something broke off the belt run or fell into the belt run and damaged the belt the tension is way loose.
i would be checking the tensioner roller pivot bushings and the waterpump,
also remove the left cam gear bolt after fitting 3 small bolts to the rotor holes so the pulley wont turn on the cam / spider,
You would be looking for a snapped left cam snout.
i would be checking the tensioner roller pivot bushings and the waterpump,
also remove the left cam gear bolt after fitting 3 small bolts to the rotor holes so the pulley wont turn on the cam / spider,
You would be looking for a snapped left cam snout.
06-26-2011, 03:58 PM
#24
Team Owner
left side is the left side of the car or the driver side.
NOTE the cam that usually has a broken snout is the driver side cam, once the bolt is removed then the cam snout falls off if its broken or you will find that the bolt that holds the cam pulley on is bent
NOTE the cam that usually has a broken snout is the driver side cam, once the bolt is removed then the cam snout falls off if its broken or you will find that the bolt that holds the cam pulley on is bent
06-26-2011, 03:59 PM
#25
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Been thinking this aswell, but wouldn't a snapped cam allow the gear to stay in place with the belt?
06-26-2011, 05:28 PM
#26
Burning Brakes
Ouchh, 7 teeth off seems a lot to me.
Once had an alfa V6 that skipped 5 or 6 teeth, and practically all valves in that head were busted.
Hope you have more luck. Fortunately the belt did not break and (possible) damage seems limited to one head only.
Really curious to find out the cause of this problem.
Cheers
Michel
Once had an alfa V6 that skipped 5 or 6 teeth, and practically all valves in that head were busted.
Hope you have more luck. Fortunately the belt did not break and (possible) damage seems limited to one head only.
Really curious to find out the cause of this problem.
Cheers
Michel
06-26-2011, 06:46 PM
#27
Under the Lift
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Yikes, Charley! Did you get a low tension warning? I guess we have more to do on Wednesday than I thought. I will bring more tools. I have a new belt and other parts for a timing belt job which we will have to do before attempting a leakdown.
06-26-2011, 07:34 PM
#28
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Thread Starter
Never got a belt warning. I should have all the tools we need, Bill. Unless you have a reason for me to leave the pully's and belt at this stage, for anything you might want to check, I'll go ahead and finish the tear down.
06-26-2011, 09:27 PM
#29
Team Owner
just make sure the crank is at 45 BTDC before you try to turn the cams or remove the belt,
be on the lookout for an errant piece inside the belt run or at the bottom of the center timing cover,
for the belt to have gotten this loose another part would have to have failed.
Could be either
a damaged tensioner roller
or a failed WP bearing
or a broken cam on the left head( driver side)
or some other part that fell down into the belt run.
Sorry to see this Charlie
be on the lookout for an errant piece inside the belt run or at the bottom of the center timing cover,
for the belt to have gotten this loose another part would have to have failed.
Could be either
a damaged tensioner roller
or a failed WP bearing
or a broken cam on the left head( driver side)
or some other part that fell down into the belt run.
Sorry to see this Charlie