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Discussion Starter · #1 ·
Hi All
This thing has got me stumped, i have replaced the hyd tensioner NTN four times because of rat tat noise coming from the tensioner/lever/pully returning them thinking they were defective...only on cold start ups for a few minutes. I have listened with a stetherscope so i know this is the place where the noise is. I am getting good at doing this job without putting the front end in the service pos...i have all the tools cam tool bar etc. I pre load the tensioner and all seems tight... seems the engine/belt/cams turning put a load on the tensioner and force the plunger down...could it be one of the camshafts tight in the journals. This all started around 120,000 , i did the belt job etc at 82k and no noise.
One more thing, when removing the tensioner it takes no effort to return the piston an put the pin back in the hole
 

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You are talking about this guy, right?


I have no experience with the V6, but on the 1.8T, but the tensioner should take good bit of effort and time to get to re-compress.

Is the noise coming from the front of the engine, or the rear?
 

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Never heard of that noise com,ing from that part. what you are describing sounds like a bad CHAIN tensioner at the back of the heads.
 

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Discussion Starter · #5 ·
Sorry guys i forgot...2001 2.8 V6....no its not the cam chain tensioners.....the noise is coming from the hydraulic timing belt tensioner %100.....as i said i used a stetherscope stuck in my ear lol... but i dont know why its doing this....has anyone else used the NTN tensioner. I dont want to pay for another tensioner from the dealer....on line $62 ..dealer $212....amaizing eh.
 

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it is the cam chain tensioner.they take a few to pump up.
I have had 2 V6's and they all do it for the first few seconds on first start up.
put the tools away and relax.
the sound will travel up there. you can put it on an exhaust manifold and hear the same sound.
there is no way in hell you have 4 bad tensioners.
here is why... cam chain attached to cam, cam attached to belt, belt rides on well you guessed it.
 

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Discussion Starter · #7 ·
You are talking about this guy, right?


I have no experience with the V6, but on the 1.8T, but the tensioner should take good bit of effort and time to get to re-compress.

Is the noise coming from the front of the engine, or the rear?
Thanks....That is the same part for the v6..but the NTN ones i got did not have the part # stamped on it, none of them did.....all the on line suppliers sell this one..but after four....could they all be defects. Not much effort to de compress
 

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Discussion Starter · #8 ·
it is the cam chain tensioner.they take a few to pump up.
I have had 2 V6's and they all do it for the first few seconds on first start up.
put the tools away and relax.
the sound will travel up there. you can put it on an exhaust manifold and hear the same sound.
there is no way in hell you have 4 bad tensioners.
here is why... cam chain attached to cam, cam attached to belt, belt rides on well you guessed it.
Thanks Scott
Yes on some morning starts, not every time i do get a little chain rattle for one second at morning starts, then no noise, coming down to 800rpm from 1000, then the tat tat noise starts...this noise is not cam chain..i know its hard to explain... tat tat it lasts until the tensioner finds its adjustments..
 

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Discussion Starter · #10 · (Edited)
How is the water pump? Bad bearings can cause the noise you hear.
W/P Roller tensioners p/s pump..etc are all ok..

Just wanted to add one more thing, when i get started on the teardowns, cold engine, i pulled the covers on the cam gears, the timing belt was always loose on the left side, turn the engine by hand and the belt tightened up after several turns on the crank pully..
 

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W/P Roller tensioners p/s pump..etc are all ok..

Just wanted to add one more thing, when i get started on the teardowns, cold engine, i pulled the covers on the cam gears, the timing belt was always loose on the left side, turn the engine by hand and the belt tightened up after several turns on the crank pully..
If the BELT tensioner is as loose as you said it is in your first post, that's why the belt was loose when the engine was cold. If it's that loose, it's only a matter of time before you slip a tooth and bend valves.

Not much effort to de compress
How loose is it exactly? Can you push the piston back in with just your thumb?
 

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How are you pretensioning the timing belt? Are you pulling the pin after you do the pretensioning, or before? If you do it right, the tensioner shouldn't pop out much at all when you pull the pin. The belt should always be tight.

I slipped on the last T-belt I did and let the tensioner fully extend prematurely. It took a bench vice and 5 minutes to recompress it enough to reset the pin.
 

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Discussion Starter · #13 ·
How are you pretensioning the timing belt? Are you pulling the pin after you do the pretensioning, or before? If you do it right, the tensioner shouldn't pop out much at all when you pull the pin. The belt should always be tight.

I slipped on the last T-belt I did and let the tensioner fully extend prematurely. It took a bench vice and 5 minutes to recompress it enough to reset the pin.
Dave i do it by the book... as with all the tensioners i pull the pin, the piston extends there is a lot of spring tension in that thing, i put the allen key socket in the tensioner pully..tension the belt, piston moves out....belt is tight between the cams/left/right . Turn the engine at the pully all is ok tight. When i did the replacements in the other tensioners i did the same thing with the allen key tool to de compress the piston, not a lot of effort......i did not need a vice..is everyone else using the NTN
 

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Discussion Starter · #14 ·
If the BELT tensioner is as loose as you said it is in your first post, that's why the belt was loose when the engine was cold. If it's that loose, it's only a matter of time before you slip a tooth and bend valves.

How loose is it exactly? Can you push the piston back in with just your thumb?
No its not that bad i would have bent valves if i could push it in with my thumb... .yes this is strange, when the engine is cold, cam covers off the belt is a little loose left side, tap tap engine running at idle...at normal temp belt is tight after engine is turned off restart hot no noise......so the tensioner has to get hot to work right.......yes every time i start on mornings ???
 

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Discussion Starter · #15 ·
How are you pretensioning the timing belt? Are you pulling the pin after you do the pretensioning, or before? If you do it right, the tensioner shouldn't pop out much at all when you pull the pin. The belt should always be tight.

I slipped on the last T-belt I did and let the tensioner fully extend prematurely. It took a bench vice and 5 minutes to recompress it enough to reset the pin.
Dave
Oh crap wait ...i pulled the pin out and the piston shot out...then i pre tensioned the belt. But i did not compress the piston before i pulled the pin... and let it out slowly... is that my problem
 

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^The last two timing belts I did with hydraulic tensioners, my V6 Passat and a V6 3000GT, the belt was pretensioned before pulling out the shipping pin on the tensioner by turning the off-center hub of the tensioner pulley until the correct torque was reached. Once the belt was pretensioned and the pin finally pulled, there was little movement of the hydraulic tensioner. In fact, on the 3000GT, it didn't move at all; the pin slid right out and easily slid right back in to the tensioner.

If the tensioner pops out when you pull the pin, I'm inclined to believe it wasn't set up properly.
 

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Discussion Starter · #17 ·
^The last two timing belts I did with hydraulic tensioners, my V6 Passat and a V6 3000GT, the belt was pretensioned before pulling out the shipping pin on the tensioner by turning the off-center hub of the tensioner pulley until the correct torque was reached. Once the belt was pretensioned and the pin finally pulled, there was little movement of the hydraulic tensioner. In fact, on the 3000GT, it didn't move at all; the pin slid right out and easily slid right back in to the tensioner.

If the tensioner pops out when you pull the pin, I'm inclined to believe it wasn't set up properly.
Pulling the pin out, the tensioner piston came about half way out of its travel, then i pre tensioned the belt tight. I would say the pin was at half way out after a few minutes, belt was tight. I dont think i need to pull it apart to do the tension thing again. Its driving me nuts why its no problem when the engine is at normal temp?
So you are saying that when the pin is pulled the piston does not extend much on the 3000GT....This problem started 47k after the last T belt job...so i replaced the timing belt and tensioner...replacing the belt was tight getting it on like the last time, so its the right belt...same part#
 

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Discussion Starter · #18 · (Edited)
^The last two timing belts I did with hydraulic tensioners, my V6 Passat and a V6 3000GT, the belt was pretensioned before pulling out the shipping pin on the tensioner by turning the off-center hub of the tensioner pulley until the correct torque was reached. Once the belt was pretensioned and the pin finally pulled, there was little movement of the hydraulic tensioner. In fact, on the 3000GT, it didn't move at all; the pin slid right out and easily slid right back in to the tensioner.

If the tensioner pops out when you pull the pin, I'm inclined to believe it wasn't set up properly.[/QUOTE belt...

This morning i pulled the left cover showing the cam and belt, i could push my finger on the belt/right side of cam going down to the W/P it moved a little bit and was not tight. I put a socket and bar on the crank pully, turned a few inches left and right..at this point the belt was nice and tight, so its working ok. It looks like when the tensioner is idle overnight, the pressure from the belt caused the oil to bleed down inside the tensioner, at that point the belt is not tight....(I took the old tensioner apart the see how it works...it has oil and a ball bearing valve) So i turned the key and started it up, at 1000 rpm the noise started, coming down to idle i used the stetherscope listening to the noise it sounded like one of those old morse code things tat..tat.. pause.. tat..until the noise disapeared just over a minute.Turned engine off belt tight.
 

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Not sure about the V6, but on the 1.8T, you have to pre-tension the belt using the tensioner roller BEFORE you pull the pin. If you don't pretension the belt, there's too much slack in the belt and tensioner can't take it all up.

The same thing happened to me when I didn't tension the belt correctly. Depending on where the engine stopped in it's cycle, there was quite a bit of slack in the belt. Luckily I caught it in time and got it tensioned correctly.

Pulling the pin out, the tensioner piston came about half way out of its travel, then i pre tensioned the belt tight.
EDIT sounds like you did it right after all.
 

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This morning i pulled the left cover showing the cam and belt, i could push my finger on the belt/right side of cam going down to the W/P it moved a little bit and was not tight. I put a socket and bar on the crank pully, turned a few inches left and right..at this point the belt was nice and tight, so its working ok.
The belt should not go slack at any time, even if sitting for a week.
 
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