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Resolved timing belt walking

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93AWDDSM

10+ Year Contributor
883
40
Jan 1, 2009
Vancouver, Washington
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Hello DSM community,

I have a problem with my T belt walking above 3500 RPMs towards the valve cover. I redid the T belt about 1200 miles ago and set to proper spec for tension on the belt. Now, it doesn't make any weird noises but when I was looking at it yesterday I noticed with the top timing cover off, the belt would walk towards the valve cover (passenger side) but at idle it was pretty centered. I have attached pictures below to give you an idea of what's happening.

I'm definitely short on funds. The tension-er had no signs of leakage when reinstalled. Also, the belt I took off a month ago when I replaced both BS and T belt - the T belt was fine, no sign of fraying..

Any ideas would be great. I'm leaning towards : auto tension-er bolts loose or coming loose. The tension-er pulley bolt coming loose causing some slack, or the back plate (for the BS belt on the crank sprocket could be rubbing against the belt

My upper timing cover was loose a little - not sure if they could have the rubbing issue but other than that, the motor sounds fine. No weird noises besides when giving gas I noticed it walks towards the valve cover..
 
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Thank you for your insight. I'll double check the tensioner+Idler pulley. both are OEM.

Could a loose auto tensioner be a problem as well? I will be posting a video of the belt later tonight showing how it's walking towards the passenger side - - - At idle the belt sits pretty much on the middle of the cams but when gas is applied the belt walks towards the valve cover.
 
i was going to say its usually a slightly bent trigger plate. especially with the tiny nicks chewed out of the belt. the plate is very easy to twist slightly if its bumped during disassembly and then it will rub the belt.
 
I did just remove the trigger plate because my BS belt snapped and was riding along it. I bent it back to original position but I'm not sure how exact I got it. Last time I did my t belt, before my BS snapped there was no fraying. I think your right about the plate behind the crank sprocket.

I know it's a no no to use a used belt but I'm in a zero option position. I had my old one that was in ok condition and I rather put that belt on then have this one frayed...until my
Motor actually decides to have a party with the pistons and valves
 
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This picture is from 1200 miles ago. I think you're right about the bent back plate... not sure how far I need to bend it back?
 
Sorry if this is a super noob question but, does a 6 bolt have a cps down by the crank sprocket? Because when I've pulled it apart many times and I've never seen that sensor?
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No it only has a Cam Angle Sensor no Crank Position Sensor.
 
Pulled the t belt and saw multiple spots where the plate behind the crank sprocket was bend towards the driver side causing issues with the chip/fraying belt. I'm on a budget for another month so I bent it back as good as I could. I'll add that part to my extremepsi for next month!

Also, the auto tensioner bolts were tight, tensioner pulley bolt was tight and same with the idler pulley bolt.

Side note: there wasn't slack in the T belt, so I'm not sure why it would be centered on the cam gears but then when reved it walks toward the passenger side/valve cover - the auto tensioner isn't leaking and seems to be holding the belt perfect :idontknow::boring:
 
Yeah but is the belt normally supposed to walk that far towards the valve cover when Reved up? Or should it stay more or less in the same position on the cams sprockets throughout the rpm?

If so should I position the belt a little more towards the driver side of the cam sprockets?
 
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Does the belt edge move past the cam sprocket edge? If not I wouldn't worry about it assuming you've corrected the belt being damaged issue. The bent plate is most likely your problem. But if you have that fixed and still have the problem, either the tensioner pulley bearing or idler pulley bearing may be worn out (loose). Also if you replaced either of those with a non-oem pulley they are famous for problems [like incorrect offset (this is very common), cheap bearing (most commo0n), cheaply made so they actually bend slightly with tension, lip is wrong thickness, etc].
Also if the tensioner pulley 2 holes are wrong way (up vs down) or rotated incorrectly while tensioning:
- http://www.dsmtuners.com/threads/timing-belt-tensioner-pulley-hole-location.30477/#post-151292535
- http://www.dsmtuners.com/threads/timing-belt-tensioner-pulley-hole-location.30477/#post-151291183
 
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Does the belt edge move past the cam sprocket edge? If not I wouldn't worry about it assuming you've corrected the belt being damaged issue. The bent plate is most likely your problem. But if you have that fixed and still have the problem, either the tensioner pulley bearing or idler pulley bearing may be worn out (loose). Also if you replaced either of those with a non-oem pulley they are famous for problems [like incorrect offset (this is the most common), cheaply made so they actually bend slightly with tension. lip is wrong thickness, etc].
Also if the tensioner pulley 2 holes are wrong way (up vs down) or rotated incorrectly while tensioning:
- http://www.dsmtuners.com/threads/timing-belt-tensioner-pulley-hole-location.30477/#post-151292535
- http://www.dsmtuners.com/threads/timing-belt-tensioner-pulley-hole-location.30477/#post-151291183
<-- move past the cam sprocket edge towards the driver side? If so, no. I assume they're OEM but I'm not positive. I've compared the tension-er pulley and idler pulley with my other 1G in the garage and they seem to be the exact same.

Great, I appreciate everyone's help. I will put it back together and if my bent plate was the issue this thread will be resolved!:talon:
 
I have the same issue with the belt not centered and pushed to the edge of the can gears. Sorry not thread jacking, just great to see I'm not alone and possible causes.
 

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I have the same issue with the belt not centered and pushed to the edge of the can gears. Sorry not thread jacking, just great to see I'm not alone and possible causes.

Were you watching your T belt walk towards the valve cover when it was running?
 
It's been like that from day one of purchase. obviously, it I never seen it from the timing cover. The edge of the belt is starting to Frey like shoe laces and the center has a rub mark down the center of the mark, also, there's a random spot with a 1/8 chunk of belt missing. I'll try and get a close up picture.

I also, noticed a whinning noise on cold start up that seems to go away as the engine warms up coming from the timing belt area. Saldy, the engine was freshly built by the previous owner so I never thought twice to look until it was to late and the timing belt started getting the markings.

If you figure out your issue, I'd really like to know because my belt position, belt freying, and rubbing marks are very similar to mine.
 

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Mine was 99% because of the bent plate behind the crank sprocket as other DSMrs stated. It's all timed and I'm going to run it tomorrow and test it. I also positioned the belt a little more towards the edge of the camshaft sprockets (driver side). I'll let you know how it turns out man.


I also have noisy timing area (balance shaft pulley) and tensioner pulley. The whine could be like mine, a timing side pulley starting to wear out. I took off my idler pulley today and compared it to my other 1g in the garage and it definitely looked "aftermarket" and had quite a bit of wiggle to it so I swapped it out with my other 1g idler pulley that was used oem. I will be replacing all the Timing components/pulleys with OEM next month from good old extreme psi
 
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I also positioned the belt a little more towards the edge of the camshaft sprockets (driver side). I'll let you know how it turns out man.

I took off my idler pulley today and compared it to my other 1g in the garage and it definitely looked "aftermarket" and had quite a bit of wiggle to it so I swapped it out with my other 1g idler pulley that was used oem. I will be replacing all the Timing components/pulleys with OEM next month from good old extreme psi
Repositioning the belt won't make any difference as it will immediately go to the position it wants to the run when the engine is started.

Yes aftermarket timing pulleys NEVER last (they ALWAYS wobble in 1/3 the time an oem one will - not to mention the offset is usually wrong) and so are never worth the cheaper price. I agree with temporarily replacing it with your used oem one as you did until you can get a new oem one.
 
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