A/C Squeal?

[jjs316]

yesterday was the first day it was actually hot enough around here to need A/C, and when i turned it on, there was a loud squeal from the engine. once the engine got warm the squealing stopped for the most of the time except for about ever 5 mins it would squeal for a few seconds.

the same squeal happened when i would turn on the defrost sometimes in the winter when the engine was cold.

I figure something maybe petering out with the A/C system, or maybe i just have a belt slipping when the a/c or defrost is on.

Also, besides the squeal, the a/c seems to kick in and kick out (air gets warmer then i feel a 'shutter' or a load on the engine and the air gets cold). I figured that was also another sign something may be going to peter out, or is this normal for a BD? other then the squeeling of course.

Anyone happen to have this problem or ever hear about it? Thanks

[Wiscon_Mark]

Sounds like a belt. Was it RPM dependant too?

[jjs316]

When the motor was cold it did it all the time, at all RPMs. once the engine got warm it did it from about 2 grand and up. when it was going away and only coming back for a few seconds was on the highway going about 70-80 at 3500 RPMs

[Wiscon_Mark]

Okay, I more meant, does the squeal change in pitch along with the RPMs?

[warrior]

This is most likely belt related. When you don't use A/C, the compressor's clutch isn't engaged and the pulley is spinning freely without any drag. Once you turn on the A/C (and defroster) the clutch on the compressor engages causing drag on your belt and more strain.

Your belts are probably dried up, an easy/quick fix is to get some Belt Dressing but that will only last a little while. It's very easy to change the drive belts on a Subaru. :cool:

[jjs316]

Okay, I more meant, does the squeal change in pitch along with the RPMs?


kinda gets louder the higher the RPM...

[ProdriveDreams]

the loading and unloading of the engine with the AC or Defroster on is normal. WHat happens is the compressor clutch engages, driving the compressor and rasing the high side pressures. when the pressure reaches a set limit, a high pressure switch dissengages the compressor clutch until the pressure drops below a certain threshold. This is normal, and it is normal for the air temperature to fluctuate coming out of the vents.

Unless the loading and unloading seems really severe like something is DEFINITLY broken, and you probably wouldn't be questioning, you would almost certainly know, i wouldnt worry about that.

This sounds to me like your belt either is odl and cracked, or needs to be tightened. I would inspect the belt for cracking, if it looks like there isnt any cracking going on i would try tightening it first, i mean worst case scenario if doesnt fix it, or your AC belt brakes, which is fine as it only drives the AC anyways.

[jjs316]

i checked the belts, they look fine, no cracks or anything. they feel pretty tight too. ill try and tighten them up a little when i get ahold of some tools.