Pesky hydraulic tensioner not staying within spec

[Tyeler18]

I've done a relatively broad search (as well as read a huge amount of the tech articles on doing a 1g timing belt) and just can't seem to figure this out.

Background- 90 AWD TSI that I'm doing a headgasket/timing belt job on for a buddy (zanderson). We're getting it all put back together with all new OEM parts and we've gotten to timing the motor. We get the tensioner right in spec where we can pull the grenade pin out of our brand new OEM tensioner as well as fit the 5/32" drill bit between the arm and the tensioner. Torque the pull bolt down to 36ft/lbs and then wait for 15 minutes to check it again. Our problem is that after 15 minutes the grenade pin is tight again and the gap is too small to fit the drill bit in.

We've retimed it 5-6 times now and tensioner the pulley in different amounts and always the same result. After about 30 seconds you can feel the pin getting hard to pull as the tensioner begins compressing again. We aren't for sure how tight the bolt holding the tensioner arm on is supposed to be but we have it at 32ft/lbs trying to hold it.

Anyone else with this problem? Bad brand new tensioner? There's no oil leaking out of it.

Cliffs- timing belt job
Brand new tensioner won't stay within spec after 15 minutes.

 

[turbogreyhound]

Are you using the 8mm threaded rod to set the tensioner gap? If not, this is the easiest way to do it, along with the 5/32 drill bit. Have to be real careful how much tension is put on the tensioner pulley to get the gap to stay set right.

 

[luv2rallye]

I've done a relatively broad search (as well as read a huge amount of the tech articles on doing a 1g timing belt) and just can't seem to figure this out.

Background- 90 AWD TSI that I'm doing a headgasket/timing belt job on for a buddy (zanderson). We're getting it all put back together with all new OEM parts and we've gotten to timing the motor. We get the tensioner right in spec where we can pull the grenade pin out of our brand new OEM tensioner as well as fit the 5/32" drill bit between the arm and the tensioner. Torque the pull bolt down to 36ft/lbs and then wait for 15 minutes to check it again. Our problem is that after 15 minutes the grenade pin is tight again and the gap is too small to fit the drill bit in.

We've retimed it 5-6 times now and tensioner the pulley in different amounts and always the same result. After about 30 seconds you can feel the pin getting hard to pull as the tensioner begins compressing again. We aren't for sure how tight the bolt holding the tensioner arm on is supposed to be but we have it at 32ft/lbs trying to hold it.

Anyone else with this problem? Bad brand new tensioner? There's no oil leaking out of it.

Cliffs- timing belt job
Brand new tensioner won't stay within spec after 15 minutes.

You probably damaged the tensioner by compressing it too fast as many guys do. When initially compressing it in a vice you must go VERY VERY slow - like steps of: 1/2 turn of vise handle, then wait 20 seconds for it to settle, then repeat, or you will damage the seals in it.

The distance between the tensioner arm and auto tensioner body is spec'd at .150 - .177 in. (5/32" - 11/64" drill bits) so anywhere in that range is ok. You don't have to be exactly where the pin slides easily as long as you're in that range. Just make sure it doesn't keep getting smaller and smaller which means your tensioner is bad.

Tensioner pulley torque spec is 35ft-lb.

 

[Tyeler18]

Are you using the 8mm threaded rod to set the tensioner gap? If not, this is the easiest way to do it, along with the 5/32 drill bit. Have to be real careful how much tension is put on the tensioner pulley to get the gap to stay set right.

No we're not using the rod as the tensioner is aleady compressed, so there was no need for it. I've been using the 5/32" drill bit as well as luv2rallye's method of pulling the pin.

You probably damaged the tensioner by compressing it too fast as many guys do. When initially compressing it in a vice you must go VERY VERY slow - like steps of: 1/2 turn of vise handle, then wait 20 seconds for it to settle, then repeat, or you will damage the seals in it.

The distance between the tensioner arm and auto tensioner body is spec'd at .150 - .177 in. (5/32" - 11/64" drill bits) so anywhere in that range is ok. You don't have to be exactly where the pin slides easily as long as you're in that range. Just make sure it doesn't keep getting smaller and smaller which means your tensioner is bad.

Tensioner pulley torque spec is 35ft-lb.

We never compressed the tensioner as it was compressed when we got it. I literally slapped it on and starter adjusting the tensioner pully to the point I can pull the grenade pin out easily. The problem is that the pin will get tight after tensioning the belt. We will get it to the point that I can pull the pin very easily and the drill bit fits right between, then once we torque the pulley after 30 seconds or so the grenade pin is tight and the drill bit won't fit anymore.

We think we figured it out though, just didn't have time to adjust it today. I think we're tightening it too far and the tension in the belt is causing it to compress the tensioner back down. We had the 2 dots at about 12 and 3 almost.

 

[banishedmunk]

the holes should be about level as close to 10 o'clock and 2 o'clock as possible

 

[Tyeler18]

From the pictures I've seen I noticed that, we had to tension a little farther though to get the pin to come out easily. I think we just went too far with it though.

 

[XiKeiyaZI]

I've NEVER had issues with the tensioner, so I can't really claim what your issue is or not. I've always just compressed it, pinned it, bolted it on, and pulled the pin out with absolute ease (IE my fingers.) It'd then rotate the crank 5 times, let it set for 15 minutes, rotate it again, and bam.. perfect. No loose belt, no slipped timing several thousand miles down the road, and I could STILL get the pin in the tensioner.

=/ So I dunno. To be honest and be completely nooby sounding.. I've never had to adjust the tensioner arm, although I made the tool to do it, and the only time I've ever jumped time was on my first DSM and the teeth on the belt ripped at the crank when taking off from a stop, it wasn't even fault of it being loose. Then again, the car had been sitting for 2 years.

 

[luv2rallye]

Notice the timing belt tensioner pulley rotate direction is opposite on 1g vs 2g:
http://www.dsmtuners.com/forums/new...ioner-pulley-hole-location.html#post151291183

 

[zanderson]

I know which way it turns. I'm doing it right, it's just that I was going too far and the tension of the belt was compressing the tensioner.

Edit: This is the owner of the car we're doing the tensioner on. Just so there's no confusion.

 

[TSIfreek]

Replace it as its damaged. I had the same problem