Timing belt is loose and frayed

Huskerbob · 05-04-2012, 05:00 PM

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.

Huskerbob · 05-04-2012, 05:01 PM

Sorry. 2001 A6 Avant, 2.8l 30v engine.

Just Me · 05-04-2012, 05:49 PM

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

Huskerbob · 05-05-2012, 02:14 AM

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?

4Driver4 · 05-05-2012, 04:54 AM

[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.

4Driver4 · 05-05-2012, 05:17 AM

Quote:

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.

Huskerbob · 05-05-2012, 05:47 AM

thanks yes I remember that from 2 months ago! Dang. There is zero tension on the tensioner pulley. I can move it by hand.

Huskerbob · 05-05-2012, 10:01 AM

Quote:

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?

SloopJohnB@mac.com · 05-05-2012, 10:11 AM

Did you pull the pin from the tensioner? JK!

SloopJohnB@mac.com · 05-05-2012, 10:15 AM

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.

05-04-2012, 05:49 PM	#3
Just Me AudiWorld Super User Garage is empty, add now Join Date: Mar 2003 Posts: 5,461	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 __________________ glenahan@vee-eff-emaildotnet

05-05-2012, 04:54 AM	#5
4Driver4 Tech Guru Garage is empty, add now Join Date: Oct 2002 Posts: 32,298	[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. __________________ 4Driver4 "Never give up the throttle until the bitter end." -RC 2005 A6 Sedan Q 3.2 (wife's whip) 2000 A4 Avant Q 2.8 (daily driver) 2003 Mini Cooper S (Fun!) 1995 Mazda Miata: the anti-Audi 1999 Mazda Miata SSB: track beotch 2003 GMC Yukon Denali XL: the anti-earth 2004 Dodge Dakota: hey, at least it's stick and 4x4

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05-04-2012, 05:01 PM	#2
Huskerbob AudiWorld Senior Member 2000 Audi A4 Join Date: Aug 2011 Location: North Carolina Posts: 734	Sorry. 2001 A6 Avant, 2.8l 30v engine.

05-05-2012, 02:14 AM	#4
Huskerbob AudiWorld Senior Member 2000 Audi A4 Join Date: Aug 2011 Location: North Carolina Posts: 734	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?

05-05-2012, 05:47 AM	#7
Huskerbob AudiWorld Senior Member 2000 Audi A4 Join Date: Aug 2011 Location: North Carolina Posts: 734	thanks yes I remember that from 2 months ago! Dang. There is zero tension on the tensioner pulley. I can move it by hand.

05-05-2012, 10:11 AM	#9
SloopJohnB@mac.com AudiWorld Super User 2002 Audi S6 Join Date: Oct 2002 Posts: 4,121	Did you pull the pin from the tensioner? JK!

05-05-2012, 10:15 AM	#10
SloopJohnB@mac.com AudiWorld Super User 2002 Audi S6 Join Date: Oct 2002 Posts: 4,121	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.