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Author Topic: 1.9l TD AAZ Timing belt tensioner pulley broke off  (Read 7478 times)

Reply #15July 29, 2018, 07:13:34 pm

libbydiesel

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #15 on: July 29, 2018, 07:13:34 pm »
Now I can see the pics in your update - I still can't see the one in your initial post.

That's not as bad as it could be.  Do the pistons all still protrude similarly above the head gasket surface?

Again, replace all that show contact.  I'd probably replace all 8 and all the lifters but that's just the way I like to do things.  If you aren't going to replace all the lifters, inspect the tops very closely for cracks or any irregularity in their surface.  ID Parts is currently selling a set of lifters for $60 which is a decent deal.  I'm not sure if the AAZ valves are the same size as the AHU.  You also need to know whether your stems are 7mm or 8mm.  AAZ came with either. 

Reply #16August 03, 2018, 05:40:44 pm

mortisetortoise

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #16 on: August 03, 2018, 05:40:44 pm »
I now have gotten the valve springs off and most of the valves out.

The exhaust valve of piston 4 was stuck slighty open after removing the spring. When trying to remove, it gets jammed into its guide. Its lifter is the one with the shattered valve contact face. This valve definitely took a good hit.

The other valves all slid out easily and do not look bent.

I sourced a rebuilt head for a great deal and am gathering the other parts for the rebuild.  I will get the engine going again with the fresh one then slowly rebuild this one for a spare.


Reply #17August 03, 2018, 06:57:03 pm

libbydiesel

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #17 on: August 03, 2018, 06:57:03 pm »
Sounds like a good plan. 

Reply #18August 05, 2018, 10:00:03 am

burn_your_money

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #18 on: August 05, 2018, 10:00:03 am »
Are you sure it's a good deal? Where is it from?
Tyler

Reply #19August 06, 2018, 09:11:09 am

Gizmoman

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    AAZ 1.9, HE 200 Turbo, 82 Vanagon, AAP 5 speed
Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #19 on: August 06, 2018, 09:11:09 am »
Are you sure it's a good deal? Where is it from?
^^^ Agreed - there is some bad stuff available for a lot less than the typical Klobenschmidt $1000. Not saying there aren't good deals on good heads - just need to make sure.
Jim W - 82 Vanagon Westy - AAZ 1.9, Mild head port, Cummins Holset HE200WE turbo, Frozen Boost WAIC, 10" Charge-pipe intake, Ball bearing IM shaft, Giles Pump, 215/70R16, AAP 5 speed Trans. 22 lbs max boost

Reply #20August 15, 2018, 07:08:43 pm

mortisetortoise

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #20 on: August 15, 2018, 07:08:43 pm »
Somebody on the samba sent me the contact of a seller that he had recently purchased an AAZ engine from. He had an extra rebuilt head and was trying to sell it as he is moving and clearing out parts. The head looks practically new with all new valvetrain components and fresh machined surfaces. He even through in a Corrado valve cover that he had adapted plus some gaskets and new head bolts. 

Reply #21August 15, 2018, 08:26:12 pm

Gizmoman

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #21 on: August 15, 2018, 08:26:12 pm »
Cool - there's some good folks on the Samba
Jim W - 82 Vanagon Westy - AAZ 1.9, Mild head port, Cummins Holset HE200WE turbo, Frozen Boost WAIC, 10" Charge-pipe intake, Ball bearing IM shaft, Giles Pump, 215/70R16, AAP 5 speed Trans. 22 lbs max boost

Reply #22August 18, 2018, 09:01:02 pm

mortisetortoise

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #22 on: August 18, 2018, 09:01:02 pm »
Update:

I am now in the process of reassembling as parts come in. I received both types of belt tensioning pulleys and their correct studs. Does anyone know if the later one is any better? The smaller stud worries me as the stud is the thing that caused me this problem in the first place. (I do not know which was on there orginally)



Also, I have not removed any pistons. Does anyone think it is worth pulling them out to further inspect? I have removed the oil pan to look from below and cannot see any visible damage.

Reply #23August 19, 2018, 02:03:28 am

libbydiesel

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #23 on: August 19, 2018, 02:03:28 am »
I think that either style of tensioner is fine.  I haven't heard of anyone else having the tensioner stud break.  Kind of a fluke.  I wouldn't worry about either stud.  I believe you need to correct slotted hole in the timing belt backing plate in order to run the later style.  I can't tell from your pics which version you have.  Your pistons do not look badly hit.  Look to make sure they all protrude above the head gasket surface when they are at TDC.  You can also sight up the rods if the pan is off to make sure none are bent.  Most likely all is fine with them, though. 

Reply #24August 27, 2018, 09:28:21 pm

mortisetortoise

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #24 on: August 27, 2018, 09:28:21 pm »
Update:

Good progress so far but ran into another problem. I finally got my last parts (new nut and belt tensioning gauge). I set the tension to 13 marks on the gauge and when I went to torque the nut to 33ft/lb, per bentley, the stud just stripped.  >:(  Do I have the wrong spec?

https://photos.app.goo.gl/mHWhNunpEPjjA6uXA
« Last Edit: August 28, 2018, 08:48:23 pm by mortisetortoise »

Reply #25August 28, 2018, 11:55:38 am

libbydiesel

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #25 on: August 28, 2018, 11:55:38 am »
Your new pic isn't showing up for me.  :) 

If you have the m8 stud with the 13mm nut then IIRC the spec is 18 ft-lbs.

Reply #26August 28, 2018, 08:46:30 pm

mortisetortoise

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #26 on: August 28, 2018, 08:46:30 pm »
Thanks.

I need to get better with these pics huh? Gotta find a good way to do it from google photos. Basically, the threads on the end of the stud are fully stripped. I've already ordered replacements and will make sure to torque correctly. This may have been why I had this failure in the first place. Whoever installed the last pulley may have been using the higher spec and started to shear the stud

 Yes I do have the M8 stud. 18ft-lb  sounds much more reasonable.

I wonder why I haven't been able to find that spec anywhere. Do you know what year they switched over to the M8 stud? 

Reply #27August 28, 2018, 11:43:38 pm

sgnimj96

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #27 on: August 28, 2018, 11:43:38 pm »
33 ft/lb is the the older 1.6 diesels.   
That stud is M10.     There's several cases of threads in the aluminum head getting stripped out with those,  I had mine strip out a previous owners helicoil - very disturbing to discover.   Ended up using a E-Z Lock insert to fix the head, not a ez job on the car but worked great.

Anyway that's probably why VW switched to a different style stud.
 The m8 studs have a few cases of just snapping off like that though,  seems like not a good trade off.

I wonder if anyone has used a 10mm tensioner pulley instead to be able to use a straight 10mm stud.
81 Scirocco 1.6D (conversion)    86 Gofl 1.6D      2003 Golf Tdi   1985 300TD

Reply #28August 29, 2018, 12:01:06 pm

libbydiesel

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #28 on: August 29, 2018, 12:01:06 pm »
Imgur is free and easy to use for hosting.  When uploading be sure to select the 'auto-resize' option and choose the size for message boards.

Reply #29August 29, 2018, 12:10:17 pm

libbydiesel

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Re: 1.9l TD AAZ Timing belt tensioner pulley broke off
« Reply #29 on: August 29, 2018, 12:10:17 pm »
I'm not sure where you are seeing 33 ft-lbs for stated for m8 AAZ tensioner locknut.  I don't have the Mk3 Bentley here at the moment.  I do have a Mk3 Haynes which says the timing belt tensioner locknut torque spec is 15 ft-lbs.  I have the Mk4 Bentley here which says the same 15 ft-lbs for the timing belt tensioner locknut and uses the same style m8 stud and locknut.  I was going from memory when I stated 18 ft-lbs and apparently my memory was faulty.

The upside to the later spring-loaded tensioner is that it is easier to get the belt tension correct.  It's still easy to get it wrong if the wrong procedure is used, but it's easier to get correct than the m10 style.  There is a tendency with the earlier tensioners to seriously over-tighten the belt which causes serious problems.  The downside to the later tensioner is that it is a more complicated piece and so more prone to failure.