I want to put a serpentine belt drive on my 1992 Jetta Ecodiesel with A/C

[larry104]

Here's a pic of my latest attempt to fix the flawed factory alternator drive on my Ecodiesel.

The adjustable idler roller forces the belt into contact with the alternator pulley, rather than pull it out of contact as does the stock idler adjuster. It works. The belt no longer slips and squeals and I've not had to tighten it every week. But the arrangement causes a reverse bending in the belt each rev, which I think contributed to a section of the belt chunking out after a month. I'm going to try a new Dayco belt and see if that works. If not, I want to install a serpentine drive and maintain the A/C. I've read, or tried to read, threads on this topic and can't figure out exactly what's needed.  Please enlighten me. Thank you. 

[burn_your_money]

DIY/FAQ http://www.vwdiesel.net/forum/index.php?topic=9599.0

FS thread (sold) http://www.vwdiesel.net/forum/index.php?topic=28752.0

That should help

[larry104]

That was the thread I was referring to. 

[burn_your_money]

The picture in the FS thread shows everything you need

[larry104]

All the parts came from a 1995 AAZ 1.9L? That's a Canada-only motor, yes? Anybody here have this setup? I will buy it. Thank you!

[burn_your_money]

Any AAZ with the serp setup (all of them AFAIK) will work.

Europe also got this engine. I think but am not certain that you can use the alternator off a 2.0 to save on shipping costs.

[larry104]

what about the a/c compressor? The Eco setup drives the power steering pump off the a/c compressor pulley. The serpentine setup has a serpentine a/c pulley/clutch/v-belt pulley to drive the power steering? What about the compressor itself?  Will the serpentine a/c drive fit the Eco a/c compressor?

[R.O.R-2.0]

prolly gonna have to change the way everything is mounted up if the power streering is driven off the a/c pump.. never seen that drive method before..

[burn_your_money]

On an AC car the compressor and alt are driven by the serp belt. The WP and PS are driven by a v-belt. All are directly from the crank. I think you might need the PS pump as well, I forget now, it may just be the pulley you need.

Like I mentioned in my IM, get the ends of the AAZ AC lines at the compressor because they are different then the ones on a MK2. You will need to get a shop to splice them together.

[R.O.R-2.0]

On an AC car the compressor and alt are driven by the serp belt. The WP and PS are driven by a v-belt. All are directly from the crank. I think you might need the PS pump as well, I forget now, it may just be the pulley you need.

Like I mentioned in my IM, get the ends of the AAZ AC lines at the compressor because they are different then the ones on a MK2. You will need to get a shop to splice them together.

there the lines that are held on with a big allen bolt right? rather than big compression fittings?

[Quantum TD]

there the lines that are held on with a big allen bolt right? rather than big compression fittings?

Yes.

Also, you can use the same setup off an AHU or 1Z motor.

I'd recommend against the conversion, unless you want to dump a lot of money into this. You'll need to cut the crank nose for the "D" shaped crank sprocket. Otherwise, you run the risk of crank nose failure. Also would need the clutched alternator pulley. Then, a compressor and spliced AC lines.

I'd start by buying a new idler pulley. If it's pitted, it will eat through belts. Rock Auto has them for $55. The part number is 068 260 940 . The same goes for the alternator pulley. Because it's stamped steel, it's more likely to be pitted. You'll have to get one from the VW dealer. It's the same as used on Air-cooled Vanagons from the 1980s (2-piece pulley). They run about $50 I think.

[larry104]

Idler pulley and alternator pulley are new. I replaced the stamped alt pulley with a turned steel equivalent, an Audi part number that I can't recall right now. It still eats alternator belts. I love this car but I'm to the point where I'll sell it if I can't fix the belt issue.

[Quantum TD]

Well, the only thing left is the AC pulley. They rarely pit, but I guess they can.

Also, check out this solution to the tension issue before you get out the gasoline and matches.

http://www.vwdieselparts.com/forum/viewtopic.php?f=8&t=10431

[larry104]

That fix suffers the same problem as mine; it bends the belt the opposite way each rev. My belt lasted a month. It looks easy to do. I may try it as a last resort with the v-belts.

OK, as I understand it here's what's needed to do the serpentine conversion.

Parts list:

1) accessory bracket
2) serpentine idler
3) serpentine crank pulley (will this bolt to the 1.6 balancer?)
4) serpentine 90 A alternator ( do I need a clutching pulley, and if so, why?)
5) serpentine A/C compressor (need new freon lines -- not same as 1.6 compressor?)
6) water pump pulley (is it serpentine? If v belt, what drives it?)
7) ps pump (will the 1.6 unit work? What drives it?)

[burn_your_money]

the only difference in load on the crank sprocket of the AAZ over that of the 1.6 is the serp belt system. 

The injection pump is different and the engine has different harmonic frequencies. Correct me if I am wrong but I don't believe that there has been enough testing with a serp setup on a 1.6 to say with certainty that it will destroy the engine.

That said, I would definitely run the clutched alt pulley, because it is cheap and easy. The crank gear on the other hand is cheap but is very labor intensive. Plus, depending on who is doing the work, leaving it alone may be better for the engine.