Hunter Thompson

This is kinda a long story, sorry.

This happened with my 1995 90 Quattro sport.

I brought the kids to a birthday parts on Saturday about 6 miles back on a VT dirt road. It was pretty rough all the way up with huge front heaves and bad washboards the whole way. When we get there I noticed a strange whirring sound. It seemed to be coming form the rear of the car. I drove it home and it got really loud for a few miles then suddenly stopped, then started again, then for loud again then got kind of quit again.

I got home thinking it was transmission related or possibly the fuel pump but after some investigation I discovered it was coming from the front of the car and it was coming from most likely the alternator or the tensioner pulley.

When I went out the next day the car would not start. The battery was dead. The battery is an old POS anyway but has always started the car for me. I played with the tensioner by hand as it seemed to be sticky and sprayed a little wd-40 in the hopes that magic would fix it.

I jumped the car and let it idle to warm up but it stalled after like 5 minutes, and didn’t have enough juice to start again.

After charging the battery overnight it started fine this morning and didn’t make the noise at first but then it started to make it again as it was sitting in the drive though line for over 5 minutes.

The battery light or alternator light never came on and when I tested the voltage across the battery it was slightly over 12 volts at idle and went up slights when the engine was revved.

I’m not sure what my question is. Can the jarring of the washboards do enough damage to the alternator to stop it from working? If so why didn’t the alternator light come on? Can I change the tensioner with the belts still in place?


Thanks,
Hunter

CRAZY_RUSSIAN

how would you change the tensioner with the belt still in place considering the tensioner provides pressure on the belt?! you should be getting about 14 volts out of your alternator. i would check all the connections first, including ground straps.

Hunter Thompson

yeah, that question didn't make sense to me when i asked it and i didn't ask it well. I think a better question is what is most likely to get shaken loose and cause the battery to die.

Hunter Thompson

i also forgot to mention before that the alternator is hot to the touch. not a little warm but hot. I guess i should just order one. Are the any good guides to installing it.

Loudgoldwing

The bearings in your tensioner pulley are dry. The dust and vibration of the washboards you went over were the final straw, and the tensioner is now shot. The WD you sprayed in did actually help temporarily, and sitting in a drive-thru kept your RPM's low enough that the friction built up more slowly. Had you left the house and hopped right on the freeway, I'd say 5 miles at most, and that at below-freezing temps, before your serpentine belt would have snapped.

Having a POS battery has strained your alternator. It might not be completely toast, however. A POS battery causes such a tremendous draw on an alternator that it's understandable that it's hot. I would recommend getting a good battery first, and following up with a new alternator if symptoms persist.

Hunter Thompson

I pulled the battery out of the other car and am getting less then 12v across the battery terminals when the car is running. I have 10-12 volts at the blue wire on the alternator but when i turn on the lights,heater, heated seats etc.. i drop to 10v at the battery terminals. I guess an alternator is in order.

hubturn

If replacing your tensioner, I'd get some advice from these experienced minds here about old versus new belt routings and correctly identifying what you have. My understanding is if you change to the new routing, a different tensioner is used and of course a different belt (I think). 12v.org has some diagrams of this. Other than one less part (the idler pulley) I don't know what the real advantage is.

GuyllFyre

Fewer parts and a shorter belt are already an advantage. Less funky routing is another. This makes for fewer points of failure.

Loudgoldwing

I would definitely agree that your situation calls for a new alternator.