How to Replace ALH Serpentine Belt Tensioner and Idler Pulley (with photos)

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Just out of pure curiosity... when I had some1 ask an auto parts shop about the tensioner, I was told they didn't have it but that they had the idler pully/assembly.

Now I have 5 pulleys. I thought - engine crank, power steering, alternator, tensioner, and ac... -

but I've heard of an idler pulley before somewhere Too. Am I just incorrect, or is that on a non-alh engine or something?
Well there is an idler pulley as part of the tensioner
https://forums.tdiclub.com/proxy.php?image=http%3A%2F%2Fpics.tdiclub.com%2Fdata%2F4569%2FR0010543.JPG&hash=3e2e634eae6f485f089a7484b354b9f2
 

KingJ416

Active member
Joined
Dec 26, 2021
Location
Canada
TDI
2001 volkswagen jetta TDI
Well the tensioner nut was stripped pretty bad so the open end wrenches would just slip.

But I got it done with the adjustable wrench/hammer combo!!

Belt is back on boys! Just gotta swap the pressurized hardline and hopefully that gets her back to running at 100% 🤞🙏
 

jokila

Vendor
Joined
Dec 3, 2004
Location
Houston, Texas
TDI
2003 Jetta GLS, Manual
Just out of pure curiosity... when I had some1 ask an auto parts shop about the tensioner, I was told they didn't have it but that they had the idler pully/assembly.

Now I have 5 pulleys. I thought - engine crank, power steering, alternator, tensioner, and ac... -

but I've heard of an idler pulley before somewhere Too. Am I just incorrect, or is that on a non-alh engine or something?
6 pulleys.
Definitely an idler pulley. It is right above the AC compressor.

See post #3
 

KingJ416

Active member
Joined
Dec 26, 2021
Location
Canada
TDI
2001 volkswagen jetta TDI
So I swapped out my power steering pressure line and while finishing up had q pretty bad leak from the banjo bolt on the rack side....

So I tried giving it a crank qnd stripped the bolt 🥺any links on where I can find q replacement?
 

KingJ416

Active member
Joined
Dec 26, 2021
Location
Canada
TDI
2001 volkswagen jetta TDI
Also when my power steering pulley bent. It chewed a slit into the plastic tubing or whatnot beside it that attaches to the EKG or EKR valve or w.e.

pretty sure it's causing a vacuum leak which is causing my power/RPMs to pulse while on the throttle.

Think I'd get away with some sheet metal tape they use for duct work until I can replace it?

Some1 told me duck tape but I feel like that silver stuff would be more air-tight and also heat-friendly. What you guys think?
 

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
That'd be a boost leak - that's hard plastic pipe (~2" diameter) running up beside the PS pulley is the from the turbo-->intercooler-->EGR/intake.

Some folks have just patched it with JB Weld and some tape to seal it and seems to do the trick.
 

KingJ416

Active member
Joined
Dec 26, 2021
Location
Canada
TDI
2001 volkswagen jetta TDI
That'd be a boost leak - that's hard plastic pipe (~2" diameter) running up beside the PS pulley is the from the turbo-->intercooler-->EGR/intake.

Some folks have just patched it with JB Weld and some tape to seal it and seems to do the trick.
Thanks man! Makes alot of sense as to why it's blowing air out and not sucking in as I thought it would!

Thought it was part of the air intake in all honesty... but anyways.. so that tees back into the intake?

Meaning it mixes with the fresh air and cycles through again?
 

jokila

Vendor
Joined
Dec 3, 2004
Location
Houston, Texas
TDI
2003 Jetta GLS, Manual
Thanks man! Makes alot of sense as to why it's blowing air out and not sucking in as I thought it would!

Thought it was part of the air intake in all honesty... but anyways.. so that tees back into the intake?

Meaning it mixes with the fresh air and cycles through again?
No mixing of air.

The intercooler is like a small radiator. It cools the incoming air from the heat generated by the compression of air whilst in the turbo. At that point in the tubing the air is under pressure on its way to the intake manifold.
 

KingJ416

Active member
Joined
Dec 26, 2021
Location
Canada
TDI
2001 volkswagen jetta TDI
Well I used aluminum tape and it seems to be a temporary fix for now. Just had to apply it in warmer temperatures.

Seems to be running better. Check engine light went off. But we got hit with some really cold days and a ton of snow today and I believe the battery's done for good.

Turns out my uncles at a vw dealership close to home so gunna get the oem battery and banjo bolt I stripped from them 🤞👍
 
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