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Timing belt is loose and frayed

Old 05-04-2012, 05:00 PM
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Default Timing belt is loose and frayed

Driving today and the car just quit. Tried to crank but it seemed weak and wouldn't start. Had the rollback bring it to my shop. Put it in service position and pulled the front covers. The timing belt is fraying from the back edge and has about an inch of play. Cams appear to be in line by the diamonds and as soon as I get the crank pulley off I'll see where that mark is. It's throwing a P0346 code, cam position sensor bank 2. I suspect the new hydraulic belt tensioner I installed about 1500 miles ago has failed. Any ideas? Appreciate the help. New parts are on order.
Old 05-04-2012, 05:01 PM
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Sorry. 2001 A6 Avant, 2.8l 30v engine.
Old 05-04-2012, 05:49 PM
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not clear what the question is. You pointed out the obvious answer.

I dont know whether an inch of travel is enough to ruin the valves if that's the ?????

Nor do i know why the part failed, except that most things are either good or bad the day they are born, and either fail early or never do. So early failure does not surprise me.

G
Old 05-05-2012, 02:14 AM
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I guess the question I omitted from my post was why did the engine just stop and then when trying to restart it cranked very slow and sounded weak. The battery is strong at 12v and has not been a problem prior to this. Would the code cause this?
Old 05-05-2012, 04:54 AM
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[QUOTE=Huskerbob;24296086as soon as I get the crank pulley off I'll see where that mark is.
[/QUOTE]

Once you get the crank pulley off, the mark will be on the pulley in your hand. Check it prior to disassembly, not after.
Old 05-05-2012, 05:17 AM
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Originally Posted by Huskerbob
I guess the question I omitted from my post was why did the engine just stop and then when trying to restart it cranked very slow and sounded weak. The battery is strong at 12v and has not been a problem prior to this. Would the code cause this?
The belt probably jumped time.
Old 05-05-2012, 05:47 AM
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thanks yes I remember that from 2 months ago! Dang. There is zero tension on the tensioner pulley. I can move it by hand.
Old 05-05-2012, 10:01 AM
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Default timing belt loose and frayed

Originally Posted by 4Driver4
The belt probably jumped time.
Oaky, I cranked it around and got my crank mark lined up and the cams are marked with nail polish from the original job, 2 months ago, and those marks are at the 11 o'clock position about 1/4 inch from vertical. They match in position.

I'm waiting for tools from Blau for my next step. Cranking the motor over by hand I did not hear or feel any interference. What are the odds and how can I tell if I bent something? Can I reposition the cams so the locking bar lines them up?
Old 05-05-2012, 10:11 AM
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Did you pull the pin from the tensioner? JK!
Old 05-05-2012, 10:15 AM
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Well, you're going to have to do something to time the engine. Since you've turned the engine without problem you might as well use the TDC tool on the crankshaft and time the cams with the timing bar (put the timing bar on, loosen the sprockets, etc.).

As I understand it your question would be how to get the timing bar on if it doesn't line up...probably put the timing bar on when the cams line up and then turn the crank to TDC the shortest distance and then lock the crank.

You'll have to get the timing bar on the cam ears first.

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