Phantom's 1997 Jetta GL IDI AAZ Manual

[phantom1260]

All pulleys seems to be a bit shiny and the old belt is wrapped around the power steering pulley & crank.

I can't recall what a shiny pulleys indicates, would that mean the belt was slipping?

AC pulley has a tiny bit of movement to it but I don't know if I can say it has play.

I did run over a small bit of snow at the end of the driveway last time I drove the car. I should have been a bit slower. Could that be enough to damage the belt?

Snow Bank Angle 1
Snow Bank Angle 2

 

[ToddA1]

He said that if the alternator is not running the oil light will also come on.

I’m not familiar with true AAZ wiring, but that sounds odd. What I can confirm is my serpentine idler bearing blew on my 1Z, and things stopped spinning. Alt light came on, but oil light didn’t.

Meh…. I calmly turned around and drove roughly 20-30 miles home, before I popped the hood to see what occurred. If that oil light came on, I’d have pulled over immediately.

-Todd

 

[Vince Waldon]

On the AAZ the alternator provides the tach signal (via a dedicated "W" connection on the far side of the diode bridge) AND the tach signal is connected to the dynamic oil pressure warning system, which changes which of the two oil pressure sensors it listens to based on engine RPM.

So... although I've never heard or seen of this effect...'tis technically possible the broken serp belt is related to the oil pressure light. Can't quite reason it out myself, but still possible.

Only way to know for sure is to fix the belt and see what happens.

 

[turbodieseldyke]

I’m not familiar with true AAZ wiring, but that sounds odd. What I can confirm is my serpentine idler bearing blew on my 1Z, and things stopped spinning. Alt light came on, but oil light didn’t.

Meh…. I calmly turned around and drove roughly 20-30 miles home, before I popped the hood to see what occurred. If that oil light came on, I’d have pulled over immediately.

Same here when I lost my serp belt. Alt light, but no oil light. I was 250mi from home, Oreilly didn't have an idler pulley, so i bought a spare battery and motored on. Good thing i disabled DRL right after buying the car.

 

[ToddA1]

On the AAZ the alternator provides the tach signal (via a dedicated "W" connection on the far side of the diode bridge) AND the tach signal is connected to the dynamic oil pressure warning system, which changes which of the two oil pressure sensors it listens to based on engine RPM.

Well, that explanation makes more sense… get the belt back on.

Same here when I lost my serp belt

I always found it strange these cars use a serpentine and V-belt. I guess it kinda works out, being the water pump is on the V…

-Todd

 

[phantom1260]

Yes this make much more sense now and hopefully is the case.

Parts are ordered and I also picked up the alternator pulley tool today which was on sale so that's a win I guess.

Going to replace the Belt, Alternator Pulley, Tensioner & Tensioner Lever. Will be spraying everything down before hand. Always scary dealing with hardware that has 25 years of rust on it.

 

[phantom1260]

Looking into this further I'm realizing I might not be able to get the old Tensioner Lever out with the engine in the car.

Seems quite long and not enough room for it to be removed. Might just cancel that part if I won't be able to get in on. I doubt that's the culprit here anyways.

 

[Mozambiquer]

You probably know this already, but probably the biggest weakness in the AAZ engine was the design of the crank snout, which in combination with a bolt that was often improperly installed and an alternator without a decoupling clutch caused the keyway to wallow out.

Given enough slippage between the crank and sprocket eventually pistons meet valves.

This can be mitigated somewhat by keeping a careful eye for lateral wobble of the harmonic balancer, as seen from above... but one can consider pulling the crank bolt at some point, carefully inspecting the snout and sprocket, and then reassembling with a new bolt torqued to factory spec, so that you know it's done right. AAZ cranks are getting pretty hard to find.

On my AAZ I also retrofitted a clutched alternator pulley...dunno if it helped but it didn't hurt and the car lived many years until I upgraded to a TDI.

I was reading through this thread and was wondering what you had done here? What's with the bolt in the end? I've always just seen them install the ina 49mm pulley for the ahu/1z which simply bolts right on. They're getting harder to find, but I got a big stash when my supplier was selling out, but then I got a pulley for the cvca/crua engines and they're identical and also made in Germany, which is good to know.

 

[phantom1260]

Got the parts installed and no more oil light or alternator light.

I'm going to say it was a combination of a bad tensioner and a non clutched alternator pulley that caused this to happen.

With the new tensioner and clutched alternator pulley the idler isn't bouncing around anymore.

Apreciate everyone's comments and insight.

 

[phantom1260]

I asked about this blocked off line before but now I took a picture of it the diagram to reference.

From the below diagram the vaccum line on the injection pump is removed and blocked off. I also found that the line from the wastegate to the change over valve was totally deteriorated. I replaced that one but I'm wondering about the one that's supposed to go to the injection pump, is there anything to gain or lose from this set up?

 

[phantom1260]

I ended up removing the plug from the line and put the line back onto the the pump where it's suppose to go. The car now idles higher when cold and once it reaches operating temperature the idle comes back down.

I also gained about 3 MPG but that might just be a difference in driving style or the warmer weather.

 

[Steve Addy]

I also gained about 3 MPG but that might just be a difference in driving style or the warmer weather.

Is Ontario using summer blended fuel yet or not? That's always a trigger point for me on mpg. I would guess no but I think we switch Mar 1 in Iowa.

Steve

 

[phantom1260]

Not sure if we've switched yet or not. But MPG aside I would say I could have used the fast idle during the winter months.

I always felt the car was idling lower than I would prefer. Right now with the fast idle activating while the car is warming up it will idle around 1100 rpm.

Previously the car was idling at around 850 but the idle was rough and still does once the car is warmed up. I've been thinking of bumping up the idle to about 1000 were it smooths out.

 

[phantom1260]

Recently I've noticed whenever I'm at a stop where the road isn't level and the car is leaning left, It becomes really tricky getting into first gear. Is this probably due to worn engine mounts with the age of the car?

I also have a temporary groaning noise whenever turning right without being on the throttle. In the rain this will continue to occur momentarily after the right turn even after straightening out until I throttle up a bit. I read another thread describing something like this being related to the power steering pump? I know I have torn CV boot on that side but I don't think that's the noise I'm hearing. CV would usually be a clicking noise from my experience.

Another sound I've been ignoring is some sort of top end (maybe lifter) noise at higher throttle.

I did notice even though I don't have any starting issues or anything there's still a constant line of bubbles in the fuel lines. Not sure if it's a fuel issue causing this noise.