Go Back   AudiWorld Forums > Audi Models > Audi A6 / S6 / RS 6 > A6 / S6 (C5 Platform) Discussion
Sign in using an external account
Register Forgot Password?


A6 / S6 (C5 Platform) Discussion Discussion forum for the C5 Audi A6 and S6 produced from 1998-2004

Timing belt is loose and frayed

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
Old 05-04-2012, 05:00 PM   #1
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
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.
Huskerbob is offline   Reply With Quote
Old 05-04-2012, 05:01 PM   #2
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

Sorry. 2001 A6 Avant, 2.8l 30v engine.
Huskerbob is offline   Reply With Quote
Old 05-04-2012, 05:49 PM   #3
AudiWorld Super User
Account #: 52472
 
Join Date: Mar 2003
Posts: 5,952
Default

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-email*dot*net
Just Me is offline   Reply With Quote
Old 05-05-2012, 02:14 AM   #4
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

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?
Huskerbob is offline   Reply With Quote
Old 05-05-2012, 04:54 AM   #5
Tech Guru
Account #: 43812
 
4Driver4's Avatar
 
Join Date: Oct 2002
Posts: 33,258
Default

[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

Growing old is mandatory; growing up is optional.

2005 A6 Sedan Q 3.2 (wife's whip)
2003 S8 (Q Ship)
2000 A4 Avant Q 2.8 (daily driver)
1999 BMW M Coupe (clownshoe)
1980 VW Scirocco (mid-life crisis car)
1983 Mazda RX-7 (revolutionary sports car)
1999 Mazda Miata SSB (track beotch, no plate)
2003 GMC Yukon Denali XL (the anti-earth)
2004 Dodge Dakota (hey, at least it's stick and 4x4)
4Driver4 is offline   Reply With Quote
Old 05-05-2012, 05:17 AM   #6
Tech Guru
Account #: 43812
 
4Driver4's Avatar
 
Join Date: Oct 2002
Posts: 33,258
Default

Quote:
Originally Posted by Huskerbob View Post
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.
__________________
4Driver4

Growing old is mandatory; growing up is optional.

2005 A6 Sedan Q 3.2 (wife's whip)
2003 S8 (Q Ship)
2000 A4 Avant Q 2.8 (daily driver)
1999 BMW M Coupe (clownshoe)
1980 VW Scirocco (mid-life crisis car)
1983 Mazda RX-7 (revolutionary sports car)
1999 Mazda Miata SSB (track beotch, no plate)
2003 GMC Yukon Denali XL (the anti-earth)
2004 Dodge Dakota (hey, at least it's stick and 4x4)
4Driver4 is offline   Reply With Quote
Old 05-05-2012, 05:47 AM   #7
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

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 is offline   Reply With Quote
Old 05-05-2012, 10:01 AM   #8
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default timing belt loose and frayed

Quote:
Originally Posted by 4Driver4 View Post
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?
Huskerbob is offline   Reply With Quote
Old 05-05-2012, 10:11 AM   #9
AudiWorld Super User
Account #: 44417
 
SloopJohnB@mac.com's Avatar
 
Join Date: Oct 2002
Location: Olney, MD
Posts: 6,052
Default

Did you pull the pin from the tensioner? JK!
SloopJohnB@mac.com is offline   Reply With Quote
Old 05-05-2012, 10:15 AM   #10
AudiWorld Super User
Account #: 44417
 
SloopJohnB@mac.com's Avatar
 
Join Date: Oct 2002
Location: Olney, MD
Posts: 6,052
Default

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.
SloopJohnB@mac.com is offline   Reply With Quote
Old 05-05-2012, 11:08 AM   #11
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

When i did all that work 2 months ago I used a new tensioner and I did pull the pin and pre-loaded it according to the instructions. Since that work I have about 1500 miles on it with no problems.
Huskerbob is offline   Reply With Quote
Old 05-05-2012, 11:10 AM   #12
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

Got it. Thanks. I need to turn the cams about 1/4 inch closkwise to get the bar on. Then loosen the cams and then re-position the crank to the TDC mark? Install the crank lock tool.
Huskerbob is offline   Reply With Quote
Old 05-05-2012, 05:41 PM   #13
AudiWorld Super User
Account #: 44417
 
SloopJohnB@mac.com's Avatar
 
Join Date: Oct 2002
Location: Olney, MD
Posts: 6,052
Default

Either one first should work since you're so close. I'd position the cams then move the crank. Replace TB, idlers, tensioner, etc. If it's more than 50K miles since you've done the water pump and thermostat I'd replace them as well.
SloopJohnB@mac.com is offline   Reply With Quote
Old 05-06-2012, 02:08 AM   #14
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

Thanks for the help SJB. I did evertyhing on the front of the motor about 1500 miles ago when I did the timing belt. This all started with a leaky thermostat so as long as I was in there I just replaced everything plus a failing alternator.
Huskerbob is offline   Reply With Quote
Old 05-12-2012, 07:02 AM   #15
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

okay, got it all apart and the tensioner has failed. It just sits there. The tensioner pulley is trashed and the tensioner arm is actually worn into 2 pieces. Also the crank pulley has a nice grove in it where a piece of the tensioner arm got stuck. How do I remove the crank pulley? Not enough room for a puller to get behind it. Thanks for any advice.
Huskerbob is offline   Reply With Quote
Old 05-12-2012, 09:07 AM   #16
AudiWorld Senior Member
Account #: 89002
 
ezveedub's Avatar
 
Join Date: Mar 2005
Posts: 809
Default

Quote:
Originally Posted by Huskerbob View Post
okay, got it all apart and the tensioner has failed. It just sits there. The tensioner pulley is trashed and the tensioner arm is actually worn into 2 pieces. Also the crank pulley has a nice grove in it where a piece of the tensioner arm got stuck. How do I remove the crank pulley? Not enough room for a puller to get behind it. Thanks for any advice.
What brand is the hydraulic tensioner? Was it OEM? Also, are you trying to take off the lower crank timing belt sprocket? If so, you need to pull the crank bolt and take off the sprocket. The bolt gets replaced also, one time use. I assume you already have the crank pulley off to get the TB covers and tensioner out.
ezveedub is offline   Reply With Quote
Old 05-12-2012, 11:58 AM   #17
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

the tensioner says NTN on it so Japanese made. Got it from Blau. So I need to remove the big 12 point 24mm bolt at the front of the crank? That will let me get that chowed pulley off? The pulley has 2 keys on the crank.
Huskerbob is offline   Reply With Quote
Old 05-12-2012, 12:05 PM   #18
AudiWorld Senior Member
Account #: 89002
 
ezveedub's Avatar
 
Join Date: Mar 2005
Posts: 809
Default

Quote:
Originally Posted by Huskerbob View Post
the tensioner says NTN on it so Japanese made. Got it from Blau. So I need to remove the big 12 point 24mm bolt at the front of the crank? That will let me get that chowed pulley off? The pulley has 2 keys on the crank.
Yes, you need to pull that 24mm 12 point bolt to get the sprocket off. The front pulley has two alignment keys that index to the crank TB sprocket. You need to have the crank locking pin installed so you can loosen and install the new sprocket and bolt. Replace the crank seal while you're in there.
ezveedub is offline   Reply With Quote
Old 05-12-2012, 12:31 PM   #19
AudiWorld Senior Member
Account #: 219486
 
Huskerbob's Avatar
 
Join Date: Aug 2011
Location: North Carolina
Posts: 1,155
Default

Okay got that part I think. The locking tool will hold so I can break that bolt? Now looking at the cams on the driver side cams the little arrows line up perfectly with the notches on the cams. On the passenger side the exhaust cam arrow is lined up with the notch but the intake cam notch is off about 1/4 inch from the arrow. Maybe one roller on the chain. Can I lift that cam and move it one roller? I'm going to do the seals on the tensioner there anyway so I'll have the cams up.
Huskerbob is offline   Reply With Quote
Old 05-12-2012, 01:06 PM   #20
AudiWorld Senior Member
Account #: 89002
 
ezveedub's Avatar
 
Join Date: Mar 2005
Posts: 809
Default

Quote:
Originally Posted by Huskerbob View Post
Okay got that part I think. The locking tool will hold so I can break that bolt? Now looking at the cams on the driver side cams the little arrows line up perfectly with the notches on the cams. On the passenger side the exhaust cam arrow is lined up with the notch but the intake cam notch is off about 1/4 inch from the arrow. Maybe one roller on the chain. Can I lift that cam and move it one roller? I'm going to do the seals on the tensioner there anyway so I'll have the cams up.
As long as the crank locking pin is installed fully, it will hold to remove and install the crank bolt. The internal cam timing marks I'm not 100% sure of when it comes to the alignment. Its been a while since I've done one. I know it's been posted on this forum before though. If I remember correctly, it was 16 rollers on the chain between the intake and exhaust cam marks. If one is off, then loosen the cams and rotate the cam in the chain when the tensioner is loosened.
ezveedub is offline   Reply With Quote
Old 05-12-2012, 01:06 PM
AudiWorld
Audi R8




Paid Advertisement
 
 
 
Reply

Tags
28, 98, a6, audi, belt, cambelt, car, frayed, fraying, frayyed, loos, loose, months, start, timing


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



Join AudiWorld

All times are GMT -8. The time now is 10:26 PM.


Copyright 2014 AudiWorld.com Audi Enthusiast Community