Hey guys! Just wanted your insight/second opinion on an issue I've been having. I have a '98 Civic DX with 71k, and recently, I've been hearing a whining/screeching noise coming from under the hood.

It happens when I'm running the A/C, and has a tendency to kick in when shifting into 3rd or 4th gear. On the freeway, it is somewhat sporadic yet frequent every few seconds, and when it happens, there is a noticeable loss in horsepower. At idle, the horrible screeching disappears, but there is still a somewhat consistent squeek.

From that description, what do you guys think? I think it's either A) My A/C belt having incorrect tension, or B) My buddy says it might be my A/C compressor clutch/actual compressor.

If it's the belt, do you guys think it's too tight or too loose? By how much should I correct it? To correct it, I loosen the pulley before the adjuster nut on the top, right?
If it's the clutch, what are my options? Is it worth putting on a new clutch, or should I just get a whole new compressor?

Sorry for all the noob questions, any input is greatly appreciated, thank you guys in advance!

 

Easy way to finalize your diagnosis - remove the AC belt. Does the noise still occur?

 

If it's still there then I'm pretty sure you'll know what to look at next but if it's not there and is when you put the belt back on again it could be the alternator belt or the actual alternator. I'm having a similar problem but I took out the A/C so I know that's that the problem. Hane's gives you the quick tip of if center of pulley to center of pulley is between 7-11 inches the belt should give 1/4in of free play. Unfortunately I know my alternator is making the whining noise and it's annoying as ****. Rock Auto aftermarket to save some bucks but it comes at a cost I suppose......

 

Thanks for the handy tips guys, it is indeed my A/C. So should I just start fiddling with the tension of the belt? It looked to be in good condition, not too many cracks per inch, no glazing.