possible timing belt tensioner problem??...timing belt too much slack?

[situcong]

my 2002 b6 1.8t AMB has 57000miles on the clock. I can feel the vibration in cabin since it was brought last year. So i replaced engine mounts, snub mount, boost leak tested, i also have the new transmission mount on hand and wanted to change it anytime soon. The vibration is still here...........................

this morning i suddenly decided to check the timing belt. I upload a video to let u guys see if there is too much slack?? i believe it's the original belt and tensioner since it's only 57000miles.

i did a 3.0 timing belt couple years ago but no experience on the 1.8, Is the tensioner gone? Could be the timing belt tensioner problem causes the vibration i am experiancing? should i try to adjust the tensioner pulley?

[CyberPMG]

You're close in miles to have the timing belt service done anyway (60-70k miles). The process is much easier on the 1.8T than on the 3.0. Get a complete kit to replace the belt, tensioner, accessory belt, water pump, and coolant flush.

[walky_talky20]

2002 on the original belt? That belt is 12 years old. Way overdue based on time alone. Change it right meow.

The tensioner is probably marginal at best. Of all the Audi timing belts I've done, I don't think I've ever pulled out an original tensioner that was good enough to reuse. They all leak and lose tensioning capability over time (revealed by free play at the end of the piston travel).

I will say that the belt looks really nice, though. The printing is all in good condition with no cracking. But the looseness is not good. Maybe somebody changed the belt only at 40 or 50k? Who knows.

[MMMB00ST_A4]

"Press testing" the belt for tension is generally not the best way to determine belt tightness. Try turning the belt in both directions as if you were trying to flip the belt over. If you get more than 45* of movement, your tension is out of tolerance. Note, this is really irrelevant as the others have stated. The belt needs to be replaced based on the age of the materials alone. Tensioners will all be replaced with the timing belt kit. Fairly easy job as well, with plenty of write-ups and walkthroughs to guide you.

[situcong]

thank you for all your inputs.

i double checked it again. i turned the engine by hand (clockwise), once it start turning, the belt tighten up like it should. Maybe it's just the engine "counter-clockwised" a little by itself when the car was reversing to the driveway and stopped. the belt lost the "pulling force" from the crank pulley. (not really sure...)

anyway, a timing belt kit should be arrived in couple days. thanks again!

[1900gte]

Audi seems to change from the hydraulic tensioner to a meachnical tensioner for the 1.8T.
The new Audi kits contain a tensioner similar to the one used for the 2.0TFSI (B7)

Also Contitech no longer has the hydraulic tensioner. (CONTITECH CT909K5 is fased out)

http://pic.ctapps.de/media/montageti...20%28EN%29.PDF

[situcong]

wow, i didnt know. it's lucky that i saw your post before i submit the order.....

I searched around. it seems like ecs doesnt sell the new tensioner.

blauparts has them. It cost $200 just for the new style tensioner+idler+timing belt!!!

do u recommend any other places ? or is it really worth to get the newer design?

[Matt Devo]

"Press testing" the belt for tension is generally not the best way to determine belt tightness. Try turning the belt in both directions as if you were trying to flip the belt over. If you get more than 45* of movement, your tension is out of tolerance. Note, this is really irrelevant as the others have stated. The belt needs to be replaced based on the age of the materials alone. Tensioners will all be replaced with the timing belt kit. Fairly easy job as well, with plenty of write-ups and walkthroughs to guide you.

I've heard 90°, but can't find an official source to confirm. The Bentley only specs setting the tensioner, not checking belt deflection

[Charles.waite]

Audi seems to change from the hydraulic tensioner to a meachnical tensioner for the 1.8T.
The new Audi kits contain a tensioner similar to the one used for the 2.0TFSI (B7)

Also Contitech no longer has the hydraulic tensioner. (CONTITECH CT909K5 is fased out)

http://pic.ctapps.de/media/montageti...20%28EN%29.PDF

Whoa!

Never knew about this. Very interesting. Having done my 2.0t's timing service last year and my 1.8t's timing service this year, I am a big fan of the 2.0t's simplified tensioner setup. Its much easier to install and get tensioned properly. Wish I had known about this change 6 months ago when I did my service. Oh well...

[walky_talky20]

Interesting. I wasn't aware they had trickled that update down to the 1.8T. That 2.0T mechanical tensioner looks a lot like the one VW used on the MK4 2.0 (2.Slow) engines. A tab to hold it still, then you wind it up and set it at particular amount of pre-load. Simpler and possibly more reliable, although probably doesn't "dampen" quite as well.

[lookaught]

I had the same problem on my car, yeah the tensioner is bad. Mine would also tighten up when running but sometimes would also run kind of slack and make a hell of a racket.

[g huns]

I can't believe that belt is 12 years old. Mine was 10, but looked 1000. The print was barely legible and it had cracks everywhere. Don't get me wrong, I'd swap it out now. For the price of parts and time it takes to change it, it's cheap piece of mind.

[Charles.waite]

Interesting. I wasn't aware they had trickled that update down to the 1.8T. That 2.0T mechanical tensioner looks a lot like the one VW used on the MK4 2.0 (2.Slow) engines. A tab to hold it still, then you wind it up and set it at particular amount of pre-load. Simpler and possibly more reliable, although probably doesn't "dampen" quite as well.

The 2.0t has a slightly oval crank pulley so the tension variations across each rotation are lessened theoretically. I read this in a self study guide a while back. Seemed clever. That plus the balance shafts make the 2.0t idle waaay smoother. But it also probably allows the tensioner to be more of a constant tension device rather than a hydraulically tensioned and dampened device like the original 1.8t design.