My 02 6MT is getting a loud screeching and whining noise when I'm picking up from a stop or very slow speed (below 10 mph). This only happened before when I had the A/C on. It now happens if I have heat on or even the rear defrost.

It's not something that happens all the time. After the car has been running for a good 10 minutes with the A/C, heat, defrost on, it usually doesn't make the noise when starting from a stop.

If the car is already warmed up and I decide to use the A/C or heat, there's still a chance of the noise coming up when picking up from a dead stop.

It's extremely loud and can be heard probably from 50 feet away. Once the noise is on, if I shut off the A/C, heat, defrost, it'll go away after a second.

If turning these on while the car is already moving above 10 mph or so, it doesn't make this awful noise.

Any ideas?

 

Sounds like the A/C compressor is going out. Defrost mode will turn on the A/C compressor to draw out the moisture from the inside of the vehicle.

 

Any chance that it could be a loose or bad belt?

 

I would inspect the belts and make sure tension is good and there's no cracks in the ribs, my infiniti started doing that and i just snugged the belt a little more and never gave me trouble any more

 

Its either the belt or the compressor. I would check the belt first.

 

Mine had some loud screeching and a lot of whining, now I just don't let the wife ride with me and it seems to have gone away. 8-)

 

Thanks guys, I'll definitely try and get that belt tightened over the weekend, and LOL @ trooplewis. thanks for the laugh

 

most likely the belt needs to be changed or tightened.

 

Update: I was able to check the belt and it turned out the A/C belt was definitely much more loose than the power steering. I tightened the belt and now the car seems to be fine. Of course, it didn't always happen, so to confirm, I might need a few days but it's looking good.

Tightening it also got rid of a little squealing noise I was getting when picking up in 1st gear or at a very low RPM (800-1000).