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Hi,

Lately, I have had some noise from the timing belt. It sounds like the belt are subbing against the timing belt cover. Its worst when the engine is cold in cold wheater, but the sound disappears/reduces when the engine get hot.
I did the Timing belt two years ago and replaced everything. I removed the upper cover yesterday and it seems that the belt are running a little bit over the edge of the sprockets. Should it be like this?



 

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If everything else looks lined-up, then maybe your exhaust cam has migrated towards the back of the engine slightly, or there's a shim missing behind the cam pulley, or something like that. Either way, over a long enough time, that will cause uneven wear on the timing belt, and uneven wear is what kills belts.
 

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So I hate to dig up old threads, but this is an issue I'm having with my wife's car. I just finished doing a top end to it, all new valves, cam chain guides, timing belt water pump and pulleys. The tensioner seems like it gave out, with the car not even having a few miles on it yet. But for some reason the belt is slack on one cam, no matter how many times I've adjusted it. So I'm going to change it, but the belt appears to want to walk right off the front of the cam gear.
 

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What car/engine, how many miles? It's common for the V6 timing belt to have some slack when the engine stops. It's the cams on one bank being pushed by the valve springs. For the belt to run off the front of the cam gear, it's likely either an incorrect part or an washer left on the engine when a timing component was changed.
 

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...But for some reason the belt is slack on one cam, no matter how many times I've adjusted it. So I'm going to change it, but the belt appears to want to walk right off the front of the cam gear.
I'll assume a V6 as PZ has. On the V6, each bank being three cylinders, the cam is usually trying to turn one way or the other due to the valve springs. However, there should not be slack, a dangerous situation. Did you use the cam holding bar, and loosen the cam bolts so the sprockets can rotate on the camshafts? If that wasn't done, the sprocket spacing might not perfectly match the belt, leaving slack.

Was the eccentric roller set, then tightened properly, so it can't rotate on its bolt? If that moved, the tensioner could't move enough to properly tension the belt. In that scenario, the belt moving out of alignment on the sprockets wouldn't be that surprising to me. Also, to reset the timing, you'd need to compress the tensioner plunger back so the temporary retaining wire can fit, pre-tension the belt with the eccentric roller, then remove the plunger wire to let the belt finish tightening. All with the holding tools of course!
 

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03 Passat 2.8 V6. I did use the cam tool, with the crank holder. The cam gears were loosened, and then I set the tension roller. I followed a write up to the T. I've done these belts before a few years ago, this is the first that's tried to walk off so I'm just quiet baffled. I'm going to try and replace the tensioner again with another new one, any recommendations on where to get one? I bought a kit that was water pump, tensioner and pulleys with a new belt. We had just got the heads redone with all new valves. I'm about to give up and just go with the 2.7tt swap.
 

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I would put the front in service position and check the alignment of the idler roller and water pump pulleys with the cam pulleys. The idler and water pump are the 2 that align the belt front to back. Use a nice flat edge to test them. I have found an extra washer stuck behind the idler or tensioner roller on multiple replacements.
 

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Would an extra washer cause it to go slack though? I'll check the pulleys to make sure maybe next weekend. There shouldn't be a washer though right?
 

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the tensioner may have been compromised on install if it was compressed to quickly while trying to adjust,just a thought
 

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Would an extra washer cause it to go slack though? I'll check the pulleys to make sure maybe next weekend. There shouldn't be a washer though right?
It should not be completely slack, but it's normal to have some slack between the cams due to the valve springs acting on the cams. If it's completely slack, the tension lever may be behind the tension roller, not acting on it. That would also explain the belt moving off the front of the cam pulley. As far as the washer, I know there is one of them behind a roller, but I can't remember if it's the idler roller or the tension roller (probably the idler).
 

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So I've been trying to get back to it, pulled it apart and couldn't find an issue with the pulleys alignment. So I changed the tensioner this time with an actual Vw unit. But I'm putting it back together and can't remember if the fan idle pulley is installed like this or not. Nobody seems to mention the crank cover being over that bracket, so is this how it goes?
 

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I can't remember, but you notice when it's in the wrong spot as the plastic bends. I think you have it right and it hits the pulley if the plastic cover is over the fan clutch bracket. Plus, the bracket would be clean if the plastic cover went over it.
These 2 writeups look to be the same, as they show the fan clutch bracket being removed before the plastic cover:


 

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Well there's some small amount of relief, the engine doesn't sound like a runaway chainsaw now. I'm sure that tensioner must have been bad right out of the gate... I finished putting it together in the rain tonight, so here's hoping I got it all. No bolts left over so that's a win. I did also have to replace the fan idler, as I bent mine.
 
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