86 Jetta build

[JamesT]

Sounds like you may have a bad coolant temp sender telling the car it's warm when it isn't. Check the resistance on it when cold.

[Baron VonZeppelin]

I've got three Mk2 Jetta DZLs - all with A/C and pwr str.
No probos with the belts.
And all my pullies are clean.

But have read of some folks having various troubles before.

[92EcoDiesel Jetta]

I've got three Mk2 Jetta DZLs - all with A/C and pwr str.
No probos with the belts.
And all my pullies are clean.

But have read of some folks having various troubles before.

Interesting, I think you are the only person on this forum that I've read about with no problems with their alternator belt tensioner an an AC/ pwr steering equipped MK II. My pulleys are fine- no grooves in them. I even deglazed them with sand paper which did not help (with the OEM spec belt). I tried a Continental, a Gatorback, a Dayco, they all squealed at every engine start for about 20 seconds winter or summer and needs constant tensioner tightening till the belt is stretched to the limit with no more adjustment possible. The Gates Power Rated lawn mower belt fixed all that.

[Baron VonZeppelin]

I don't know exactly for sure what determines which cars have the problem, and which ones don't. Haven't encountered it - and hope not to. But have certain theory.

Friend of mine also has two Mk2 Dzls that are both A/C but without Pwr Str.
Never had problems with belt squeel on them either.
Same arrangement on the tensioner.
I do all the service on them, so would have gotten a report about it.

I service a number of other Mk2 Dzls here and there for other folks also, everyone i have worked on has been A/C equipped at minimum.
No belt issues.

In my mind (whats left) i think the cars past has a lot to do with it.
Lack of care and being let go for long periods, bad belts and bad bearings/bushings being run into the ground previously, etc ...

When a spec belt squeels, but a wider belt that rides higher does not, there has to be compromise in the lower sections of belt grooves. Perhaps not detectable to naked eyes.

My daily is an 89 A/C P/S with about 375,000 miles on it.
If the design were at fault - this one probably should have faulted by now.

Not debating that you or others have had previous issues.
Maybe NC is an ideal habitat for pullies ... idunno

Your fix was a smart and cost effective method  btw 
Will try to keep that in memory in case the need ever arises.

[R.O.R-2.0]

the gasser cars had the same belt layout, and tensioner setup, and NONE of those had issues..

ive owned lots of VWs with p/s and a/c, and none of them really gave me any issues so to speak.. it was a B!TC# to replace the alternator belt, but thats it..

[JBG3]

Sounds like you may have a bad coolant temp sender telling the car it's warm when it isn't. Check the resistance on it when cold.

im gonna check this out first thing, what should the cold resistance be?  is this something i can find in the bentley?

[JBG3]

I purchased a new belt, and installed it to get the car someplace where I could take a better look at the belt setup, and it was WAY shorter than the belt that was on there.  I moved the alternator almost 2 inches down to fit this new belt.  Im thinking this belt problem was a wrong application V-belt from the beginning.  It was on there when I got it, and looked pretty new with no cracks or anything, but was quite a bit longer than what turns out to have been the stock belt length.

Im going to take a better look at it tomorrow and make sure, but maybe I won't have this same problem. 

[JBG3]

I purchased a new belt, and installed it to get the car someplace where I could take a better look at the belt setup, and it was WAY shorter than the belt that was on there.  I moved the alternator almost 2 inches down to fit this new belt.  Im thinking this belt problem was a wrong application V-belt from the beginning.  It was on there when I got it, and looked pretty new with no cracks or anything, but was quite a bit longer than what turns out to have been the stock belt length.

Im going to take a better look at it tomorrow and make sure, but maybe I won't have this same problem. 

It loosened AGAIN.  I drove the car about 30 miles since putting on the new belt, and it had visibly loosened!  Just to clarify, im not undertightening these bolts, im getting close to shearing them off im applying so much force!

This upcoming week, I have to make another business trip, so I tried to solve the problem this morning.  First thing I did was increase the idle speed a bit, trying to get rid of idle vibration that might be contributing. 

Then I made a tensioner with the pulley tensioner bolts from the A/C parts motor.

Here are a few pics-

this is the original steel tab that the alternator keeps sliding on and off with the A/C tensioner bolts-



And the little tensioner doohickey I welded up-




And heres a before and after with the tensioner-




And how it looks with the alternator installed, bolt had pretty decent access-



If it loosens after rigging that up, ill be amazed, but ill keep my eye on it, I no longer trust this simple belt setup.     I also while doing this dealt with a misaligned water pump pulley, so hopefully, im done with v belt problems for the moment!  fingers crossed!

Also this morning, I upgraded the fuel filter with a Racor 500FG toploader water separator.  Last week I had clogged the original fuel filter, and had to rig up an emergency replacement to get home.  heres a before and after.  (also did another coat of rubber coating, I love that stuff). 




The car should be ready for this weeks business trip!  I still have to fix the heat and get a radio in there though, one or the other needs to be done pretty soon. 

[92EcoDiesel Jetta]

Nice job! I am glad you made your own simple tensioner (that works) instead of the VW Mickey Mouse tensioner. 

[JBG3]

Nice job! I am glad you made your own simple tensioner (that works) instead of the VW Mickey Mouse tensioner. 

Thanks!  80 miles since doing it, and its still nice and tight, so tentatively, im calling that little issue resolved!   

[JBG3]

Sounds like you may have a bad coolant temp sender telling the car it's warm when it isn't. Check the resistance on it when cold.

Thanks for this post!

I didn't have a volt meter with me, but I did a quick experiment.  When the car was sitting after being driven a couple hours before, and after it cooled down, I pulled the temp lead from the end of the head, and the glow plugs started working every time I turned the key!  I plugged it back in, and they stopped.  I left it disconnected for now, but that sensor must definitely be bad.  Engine was stone cold. 

I thought this might affect my fan coming on, but that still does that, so it must be more of a wiring issue behind the dash I have to trace. 

[92EcoDiesel Jetta]

Make sure you don't have ac turned on which would put fans on constant .  On my 92, extreme right position of ac slider knob also put the fans on constantly. Only the position immediately left of extreme right are the fans not constantly on. Not sure if this is correct or not but that's the way my car behaves.

[vanbcguy]

Sounds like you may have a bad coolant temp sender telling the car it's warm when it isn't. Check the resistance on it when cold.

Thanks for this post!

I didn't have a volt meter with me, but I did a quick experiment.  When the car was sitting after being driven a couple hours before, and after it cooled down, I pulled the temp lead from the end of the head, and the glow plugs started working every time I turned the key!  I plugged it back in, and they stopped.  I left it disconnected for now, but that sensor must definitely be bad.  Engine was stone cold. 

I thought this might affect my fan coming on, but that still does that, so it must be more of a wiring issue behind the dash I have to trace. 

There's 3 separate temperature sensors (4 if your car has AC)

- Glow plug sensor (the one you disconnected)
- Gauge sensor (for the dash gauge)
- Rad fan sensor (in the radiator itself)
- AC 'overheat' cutoff (cuts off the AC if the car is running too hot)

So the glow plug sensor being disconnected won't be related to the fan at all.  There's actually no wiring in the dash whatsoever related to the rad fan on non-AC cars, I don't THINK there is on AC-equipped cars but I can't say from personal experience as I don't have one.

[srgtlord]

My belt got to the point where it cracked from being continuously tightened. V belts are simple, but a pain in the royal arse when they keep looseneing up..... If this still does not fix your problem find another complete set off pulleys + alternator

[JBG3]

more problems with this alternator, but this time not a tensioning issue.  The alternator has started to make an absolutely horrible noise, I think a bearing is going.  What a crappy reman, this is about 3500 miles of service before failure.  Its still charging, but I don't dare go any distance without actually resolving this and replacing the unit. 

This car can't really get any simpler, this is becoming extremely irritating to continue to have problems with one of the two aux loads, water pump and alt.   

Some improvements on the way, my summer teardrop rims should be almost done with powdercoading, and that should bump up how the car looks quite a bit, and I finally pulled the dash and replaced it. 

I found lots of mouse nesting issues, and for the first time ever, the car doesn't smell!  This is a milestone event, it actually smells pretty decent now. 

Additionally I have uncovered the climate control door issue on the Mk2 where all the foam is gone, and the perforated redirect doors are exposed.  There appear to be two doors, one much further in that I may have to pull the entire unit and take it completely apart in order to get the heat working properly. (not that I need it any more, but i want to get this resolved so I can put the dash in permanently afterwords, right now its tentative.

Has anyone dealt with the climate doors, how did you resolve it?  I was reading about people using duct tape and flashing, but I want to do this nice and permanent