Serpentine Belt Tensioner - Right/Wrong Install?

peace_of_soul

Well-known member
Joined
Jul 17, 2008
Location
Indianapolis, IN
TDI
2000 Jetta, 2012 Passat
If you'd like to skip the back story and the realization of the cold hard truth that has dawned upon us, the question is in bold at the end.

After replacing the A/C compressor this summer, cleaning the intake manifold (so clogged the car could barely get into second gear without serious babying; it's MUCH better now), replacing the rear brakes (hint: never let a weekend warrior with $25 total in tools and a Ford Focus "help" you with anything), and replacing the dual mass clutch with a single mass, we are learning a lot more about the car than we ever realized we want to. Strangely enough, it's actually been a great adventure, and well worth doing. It's a good thing to look under the hood of a car, be able to identify things, and not be intimidated to have a go at making repairs.

All that said . . . we had to replace the serp tensioner, a project we undertook about a week and a half ago, while we had "Ella" torn apart for the intake manifold cleaning. The weather has gotten substantially colder, and we're running into an issue with the tensioner. Is there only one way to install the tensioner or is it possible to do it multiple ways, but wrong? For whatever reason, the plastic tensioner that is supposed to rest on the belt and, :eek: shocker :eek: , give it tension, is not really anywhere near the belt. Were we supposed to adjust the tensioner when it arrived to get it at the right angle or did we perhaps put in the three bolts wrong?

Looking forward to the sage advice, as always.

Eric and Alison
 

peace_of_soul

Well-known member
Joined
Jul 17, 2008
Location
Indianapolis, IN
TDI
2000 Jetta, 2012 Passat
Just ran a search and can't even find a picture of a serp tensioner installed in a car . . . does anyone have any they can post quickly to resolve this conundrum?
 

Keith_J

Veteran Member
Joined
Apr 12, 2007
Location
West
TDI
2000 Jetta MT
I did mine without any reference to the manual. It only goes on one way. Now the belt routing...that took some reference. Let me drag something up...
 
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ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
Silly questions:

Are you sure the replacement tensioner is for an ALH motor ???

Are you routing the serpentine belt correctly ??? [edit: I see that Keith-J got there first with this one...]

Yuri
 

whitedog

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Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Is it possible that the tensioner came with some kind of locking pin to keep it retracted?
 

yetta0

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Joined
Jul 2, 2003
Location
KW region, Southwestern Ontario
TDI
Jetta,2000,Cheyanne Red
I've replaced 2 tensioners in the past and they both came with locking pins. I can't recall whether they are in to removed after installation or not but that doesn't matter. If you have the tensioner out on a table, just unload it to get the pin out. It only moves one way anyways. There is also only one way to install the tensioner with the 3 bolts. I just had mine off for a timing belt change yesterday.
 

peace_of_soul

Well-known member
Joined
Jul 17, 2008
Location
Indianapolis, IN
TDI
2000 Jetta, 2012 Passat
ymz said:
Are you sure the replacement tensioner is for an ALH motor ???
We got the part from Joey at WorldImpex, and I'm confident he didn't sell us the wrong part.

As for the tensioner pin . . . does anyone have any suggestions on where to look for said pin??
 

Keith_J

Veteran Member
Joined
Apr 12, 2007
Location
West
TDI
2000 Jetta MT
Is this the part?


In the belt routing diagram below, the wheel is "hanging down". The wheel pivots on the hole above it, swing the wheel arm forward to relieve tension and allow the belt to be slipped on.

IIRC, an open end wrench in the 17-19mm range is used to swing the arm.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
Keith_J said:
..an open end wrench in the 17-19mm range is used to swing the arm.
16mm box-end, to be precise...
Keith_J said:
..swing the wheel arm forward to relieve tension and allow the belt to be slipped on..
Actually, when the tensioner assembly is in place, you "swing" the pressure idler towards the rear of the vehicle...

If there's a pin holding it "closed" you have to perform the same compression motion to relieve the pressure on the pin so that it can be removed...

Yuri.
 
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Keith_J

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Apr 12, 2007
Location
West
TDI
2000 Jetta MT
ymz said:
16mm box-end, to be precise...

If there's a pin holding it "closed" you have to perform the same compression motion to relieve the pressure on the pin so that it can be removed...

Yuri.
THAT IS IT! I think I can say I am officially over the hill. Now I remember is the the largest combo in my smaller set...the best damn Taiwan tools I ever bought:eek: . Yes, this Taiwan comboi set is as good as my 1970s Craftsman set.
 

gallaj01

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Joined
Mar 25, 2008
Location
Madison, WI
TDI
2002 Jetta Wagon TDI GLS, 2001 Jetta TDI GLS, 2017 Golf AllTrack
I had to replace an alternator on an '03 jetta this fall and therefore had to take off the serp belt and tensioner. IIRC there is NO lock pin on the tensioner. What worked best for me is, before taking it apart take a good look at how the serp belt routing is. Make or acquire a diagram like the one posted above.

When reassembling my recommendation is to get everything bolted on and torqued to spec, including the tenioner. Then, start routing the belt through its path. You won't be able to put it on because of the tensioner. So, what i did is get it routed on everything except the AC compressor. Now, use the wrench or appropriate serpentine belt tensioner tool to push on the cast tab next to the tensioner pulley. Swing it toward the windshield (back and up) strong and steady force will accomplish this. Then with the tension off the belt will slack and you can put the belt over the AC pulley. I recommend using a tool to slide it on else you could have some hurt fingers.

Here is a link that will help as well. Good Luck!

Serpentine Belt Change
 

kristov

Veteran Member
Joined
Jul 14, 2005
Location
Kitchener
TDI
2000 Jetta
gallaj01 said:
I had to replace an alternator on an '03 jetta this fall and therefore had to take off the serp belt and tensioner. IIRC there is NO lock pin on the tensioner. What worked best for me is, before taking it apart take a good look at how the serp belt routing is. Make or acquire a diagram like the one posted above.

When reassembling my recommendation is to get everything bolted on and torqued to spec, including the tenioner. Then, start routing the belt through its path. You won't be able to put it on because of the tensioner. So, what i did is get it routed on everything except the AC compressor. Now, use the wrench or appropriate serpentine belt tensioner tool to push on the cast tab next to the tensioner pulley. Swing it toward the windshield (back and up) strong and steady force will accomplish this. Then with the tension off the belt will slack and you can put the belt over the AC pulley. I recommend using a tool to slide it on else you could have some hurt fingers.

Here is a link that will help as well. Good Luck!

Serpentine Belt Change

There is a lock pin on a new tensioner unit typically, helps it fit in a smaller box ;)
 

peace_of_soul

Well-known member
Joined
Jul 17, 2008
Location
Indianapolis, IN
TDI
2000 Jetta, 2012 Passat
Right you are, Tom. Thank you so much for your help

The tensioner pin has been thwarted, and the oilpan is correctly installed.

I can tell a difference with how well she runs now, after the intake manifold cleaning. Hmmm, I think we may have her in pretty decent shape for a little while...

Now, I'll just have to convince Alison to let me get a Panzer plate for the "we" car.
 

tigers2007

Veteran Member
Joined
Feb 8, 2010
Location
Michigan
TDI
'97 Passat TDI Sedan (B4)
I just did mine today and it almost turned into a disaster. The old tensioner was very simple to remove. I removed the top engine cover, unhooked the fuel lines and put them out of the way and also unclamped the tube that goes into the EGR so I could push it to the side easier. The assembly comes out from the top if you wiggle it around a little bit. The new tensioner had the pin installed. I figured it would come out effortlessly after applying some torque on the 16mm torque nut on it.

Well it didn't go that easy. I almost stripped the the torque nut on the tensioner due to it being made out of aluminum. I ended up jacking the car up and placing a wooden block on a jackstand and then lowering the car down; with the wooden block, on the jackstand, putting upward pressure onto the tensioner therefore releasing the pressure on the horizontal pin. The pin pulled out with no problems and life was then good.

If I could do this all over again, I would consider removing the pin prior to installation.
 

cucamping

New member
Joined
Feb 20, 2009
Location
NE
TDI
2000 Jetta
is that long black tube supposed to be like a tension spring or something? When I try to move my pully it is not going as described above.
 

tigers2007

Veteran Member
Joined
Feb 8, 2010
Location
Michigan
TDI
'97 Passat TDI Sedan (B4)
The pin you want to pull is very small. You have to actually put tension on the pulley assembly to take it out. If you saw my above post, I opted to leave the pin in and then tried to pull tension to release it AFTER I installed it. Well it was a real pain in the a$$ and I almost destroyed the "fake nut" that you put the wrench on.
 
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