AAZ serp belt tracking problem - page 1 - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• AAZ serp belt tracking problem by Limey on 05 Mar, 2009 19:03
• yo, been racking my mind trying to figure out wtf is going on with my rebuilt aaz's multi rib belt...maybe someone else has had this problem, the dealer "had never heard of that" hahaha
  
  well the other morning 2 mins after getting off the highway, going up a hill the serp belt shereded and un-wraped untill it was 1/2 inch wide with a bunch of noise...but lucky for me after some steak-knife-under-cell-phone-light belt triming i was on my way....turned out the belt had rode off the water pump pulley in to the power steering belt...i replaced the belt after work and noticed a ridge on the outside edge of the pulley and it was worn where the belt has been riding for 275k (see picture of old pulley)...i filled the edge off and the new belt lasted 25mins till same deal happened.. guess the edge was keeping in on...notice how far over the belt rides in the picture, looks like its been doing it for a long time.. the pulley was tapered .007'' so i decieded to replace it with a spanking new oem pulley..
  
  old pulley:
  
  
  
  New pulley, another new belt, and it still wants to ride in the same spot...now when the engine is stopped, the belt sits true as can be, but as soon as you fire it up it runs right back over to the same spot
  
  engine stopped:
  
  
  engine running:
  
  
  
  engine running from bottom:
  
  
  angle of belt between balancer and pulley, engine running:
  
  
  
  now the engine has about 1000kms on it, i did not take any of the front mounts off during the rebuild (pump bracket ,alt bracket, water pump housing etc). it did get new balancer, water pump insert, roller, tensioner, one way alt pulley which is pretty much everything involved...
  
  I've played with the alt, well as much adjustment as the bolt holes give you and it didn't change a thing so the alt is now back to centered in its mount. The motor is running now with its new pulley and belt, although still on the outside of the pulley doesn't move when i rev it up...
  
  my next move i think will be to loosen the water pump bolts and see where its sitting, maybe its sitting on one side of the bolt holes or something but really how much would that make a differance??
  
  
  Any idea's would be very welcome
  
  
  The car:
  
• #1 by the caveman on 06 Mar, 2009 14:57
• My guess is that the water pump bearing may be going. That's why it's bending up when running??
• #2 by Limey on 06 Mar, 2009 17:07
• Thanks for the reply...the water pump has 1000kms on it and even before the rebuild with the old pump and by the looks of the old pulley its been riding there for a long time....
  
  one guy at the shop today asked "WTF is the ribbed side of the belt doing running on a flat pulley?" very good question in my opion but what ya going do..lol
• #3 by the caveman on 06 Mar, 2009 18:10
• one guy at the shop today asked "WTF is the ribbed side of the belt doing running on a flat pulley?" very good question in my opion but what ya going do..lol[/quote]
  Of course! you have the configuration wrong somewhere. a flat pulley must only have the flat side on it.
• #4 by Limey on 06 Mar, 2009 18:54
• This is a stock AAZ and my buddies 97 is the same, a straight shot down to the WP...after he said that, i checked it out when i got home and there is no clearance between where the belt runs from the roller to the alt and the water pump to the alt if the belt was looped around the pulley...
  
  I'm beginning to wonder if I'm thinking way too hard about this and it will be something simple, but I've searched deep into the web and haven't seen anything about this problem...i found a VW service notice about the timing belt but nothing involving the mutli rib...that notice is where i got the idea of the water pump housing being not centered in the bolt holes which could cause it to angle the pulley up a CH...
• #5 by the caveman on 06 Mar, 2009 20:16
• Quote from: "libbybapa"

  As much as it doesn't make sense, that is the correct configuration.  1Z/AHU is the same.  Ribbed side of  belt on flat pulley.   :?
  
  If you loosen the serp bracket nuts and waterpump bolts, there is play in either one.
  
  Andrew

  
  That could be and i i do think you are right, however it's got to be the only motor out there with the belt running like that. kinda stupid if you ask me.
  i'm gonna have to see for myself .
• #6 by the caveman on 07 Mar, 2009 13:09
• Okay lippypapa of course you were right. I had a look at mine and sure enough i am now remembering that it is the way they are configured. However that's not helping our friend here is it.
• #7 by burn_your_money on 07 Mar, 2009 15:37
• Does your crank wobble?
• #8 by jtanguay on 07 Mar, 2009 15:50
• Quote from: "burn_your_money"

  Does your crank wobble?

  
  
  yea the 1Z/ALH TDI's (as well as new TDI's) aren't immune to the crank failure.  mine had to be welded up because it was too loose.  even a small bit of play can result in damage over time.
• #9 by Limey on 07 Mar, 2009 19:35
• Quote from: "burn_your_money"

  Does your crank wobble?

  
  
  That was the reason I rebuilt it kinda a while its out type of thing....i caught it really early but the damage was done so out came the crank to be modded at passanger for the tdi gear and it's now striaght as an arrow
  
  It ran today just fine, the new pulley is helping the belt not move over to far, its back to the outside edge of the pulley when running but doesn't go any farther....the new wear marks match the ones on the old pulley but i really want to get that bastard centered...
• #10 by the caveman on 08 Mar, 2009 09:09
• I know it's not easy to NOT hard to  line everything up when re-installing i.e. the water pump, alternator bracket etc, but could something be out of place ? can you get a straightedge or yardstick on the pulleys to see if a component is out of line. saw that once when german steriod boy put a water pump back on with airtools and didn't tighten the bolts evenly.
• #11 by Limey on 08 Mar, 2009 14:47
• Well I played with the water pump mounting and there is an amount of movement avaible....i tryed moving the pump to the far counterclock-wise on the studs to pull the bottom of the pulley in, and it still wants to run on that outside edge...but it is a little better....I ran out of time and will to move the pump again but i will contine playing with it this week after work..
  
  I'm considering making a spacer out of some shim material to step the wp pulley out a 10 or 20 thou..at least to see if the belt wants to contine to pull right to the edge or will only go to over to where it is now....BUT this does not solve the real problem even though it might "fix it" ie stop the belt from coming off...
  
  ok so far, brand new pulley helped a bit, following the bentleys method of tighting the alt helped a little but not really, moving water pump helped the most but its still not perfect
• #12 by the caveman on 08 Mar, 2009 20:29
• Isn't it possible for the water pump hub to be moved on the shaft. I seem to remember doing that once or twice.
• #13 by the caveman on 09 Mar, 2009 16:12
• Just did a water pump today on my friend's AHU. The hub can be moved on the shaft as i thought. may need a small puller though.
• #14 by Limey on 11 Mar, 2009 17:23
• ok so been running the car past few days and hasn't kicked the belt off but its still running to the edge of the pulley but doesn't move with more rev's....will try more this weekend to get that sucker over
  
  but....i did notice that my new tensoinor is really stiff...with the newfy wrench on the arm it takes alot of effort to pull the roller back then when you release it, it SLOWLY (like 10 sec+) returns to its rest but its stiff both ways...there was just alot of spring in the old one....is there suposted to be drag? belt tension seems good but there is a small amount of flapping during rpm changes inbetween water pump and balancer