God-awful A/C squeal

[Hippo393]

well those pressures are a bit low. so I would say not over filled .

try this method before shutting down engine turn off ac for a couple of min .. then see if it squeals on the next cold start.

could be the ac system is low on oil or the compressor is failing.
I would next step add a couple of OZ of oil to the system. make sure you use the correct oil and viscosity. see if that helps. older systems do over time loose oil ..

I'll try that. I'll be a dirty bird if that works.
I've never had to add oil to the system...is that done by the compressor service valve, or just thru the regular means as if adding more refrigerant? That I can probably figure out, but any advice is greatly appreciated. BTW I have a new Toyota compressor $$$$ ready to install, but I figured I'd need to get to the bottom of this issue for my own dang knowledge. :beer:

 

[Hippo393]

I know you've said you've done your own AC work for a long time but if your pulleys move freely and feel smooth, it sure sounds like the belt isn't tensioned correctly. A properly tightened belt should have 1/2"-3/4" of deflection. If you have a tension gauge, that's even better.

Here's a video [MENTION=102606]infamousRNR[/MENTION] and I made for replacing the belts and properly tensioning them.

<iframe width="560" height="315" src="https://www.youtube.com/embed/Zi1XfFUOjKc" frameborder="0" allowfullscreen></iframe>

Tim,
Thanks for that video, it was awesome and very well done! Many, many kudos. Both you and the cameraman have had great experience in this line of work. :yo:
Getting to the bolts on the power steering is a huge PIA. I just bought ratcheting metric wrenches like you showed which should help, as the brand new A/C belt I JUST put on now has about 12-15 cumulative seconds of "God Awful Squeal" on 'er. BTW I noticed the beer bottle near the end of the instructional video before it was featured, lol.
Anyway, I do feel that my tactile measurements with belt tension are on par with what a tool would/could do, and I've experimented on this very project with tighter and looser tensions with the same results--the clutch siezes when cold regardless of the tension. GAH!!!

 

[Hippo393]

Sounds undercharged to me. High side is usually 2x the outside temp +50 give or take a few psi numbers.

The squeal, if not the belt, can be the bearing going south.

How is static pressure?

LittleCaesar, thanks for helping out this poor Ohio State Buckeye fan. :third:

This is what is odd.....when cold, it is as if the compressor clutch locks up whilst the belt is turning = God Awful Squeal. After several minutes of driving without the A/C on, THEN I push the A/C button, I'll get a diminished squeal for a hot second and then everything works great as usual....I'm as cool as a YETI for as long as I drive, and if I shut the vehicle off for 15-20 minutes, it'll turn on just fine as if nothing was wrong. Is there any way that a bad bearing could be the culprit given those signs and symptoms? :noidea:

BUT, leave it overnight and then attempt to start the vehicle with the A/C on, ...="God Awful Squeal"!!

Note: for those viewing and lurking that might have similar issues, YES I am scared to death to actually push the A/C button on at any point in my drive!! For example, even though I've driven for 15 minutes or more, I make sure no one is around me, that I'm operating at low RPMs, etc., and at 0.5 seconds after pushing the A/C button, and I get the God Awful "squeal" I'll actually push the A/C button again to shut it off so I don't burn up my 2nd A/C belt...wait another several minutes and try again in an inconspicuous place. At this point, the 2nd time around it's warmed up more and the clutch then engages without much squeal, if at all. Hallelujah!! I can close all the Daggone windows and sunroof for a VERY cool trip for as long as I need to go.
People, that/this is no way to live life, and my lovely wife will tell me to get rid of this truck if I cannot fix it. Gah!!!

Not sure what you mean about "how is the static pressure"...If it means "at rest", or with no engine running, the low pressure is 71 and the Hi is 112. Is that info helpful to troubleshoot?

Please advise.

Thanks again,
-Alan

 

[LittleCaesar]

OSU and Clemson have quite the storied past no doubt.

I still say you may be a little undercharged but if blowing serious cold air in minutes then leave the amount alone IMHO.

Squeals are usually bearings, rusty pulleys and belts. Has the AC idler pulley ever been replaced?

Static pressure is a reading taken on a cold car but I don't think it is relevant here to your problem.

 

[catrains]

I'll try that. I'll be a dirty bird if that works.
I've never had to add oil to the system...is that done by the compressor service valve, or just thru the regular means as if adding more refrigerant? That I can probably figure out, but any advice is greatly appreciated. BTW I have a new Toyota compressor $$$$ ready to install, but I figured I'd need to get to the bottom of this issue for my own dang knowledge. :beer:

there are r134 cans with oil in the can for the different PAG oil viscosity. manufactures did/do change the oil spec so be sure to add the correct oil on your 97.

too much oil just reduces the efficiency of the ac.. so I doubt your system will have too much oil with its age and miles ..most likely low oil if your lucky ...

 

[redrunner85]

any results???:bump:

 

[LittleCaesar]

I didn't see the compressor was from NAPA. Is it a lifetime warranty or two years, 24k miles? I would think they would have insisted you install a new drier for warranty work.

I would just put in the new Denso compressor, pull a vacuum, and fill it. I personally wouldn't risk it killing itself, and then needing a professional flush of the system.

OTC auto parts such as compressors are a hit or miss, usually the latter. A neighbor's kid has a 99 Dodge Ram that needed a new AC compressor in March. He has gone through four Advanced Auto Sanden compressors for various reasons. He finally wised up and went back to the OEM Denso one. No problems in two months.

 

[Hippo393]

try this method before shutting down engine turn off ac for a couple of min .. then see if it squeals on the next cold start...

Welp, tried this and it squealed like Jim Carrey in Dumb-n-dumber when he asked "Wanna hear the most annoying noise in the world??"

Little Ceaser: I do not know if the idler pulley had ever been changed....would that explain cold compressor seize? I know it's the belt squealing over an AC clutch pulley that does not initially rotate until warm...just not sure what to do. I guess I could put half a can of R-134 with some oil & see if that helps. If no luck, new OEM compressor & drier goes in. I'll report back results when I get a round tuit. Thanks gang! :beer:

 

[catrains]

Welp, tried this and it squealed like Jim Carrey in Dumb-n-dumber when he asked "Wanna hear the most annoying noise in the world??"

Little Ceaser: I do not know if the idler pulley had ever been changed....would that explain cold compressor seize? I know it's the belt squealing over an AC clutch pulley that does not initially rotate until warm...just not sure what to do. I guess I could put half a can of R-134 with some oil & see if that helps. If no luck, new OEM compressor & drier goes in. I'll report back results when I get a round tuit. Thanks gang! :beer:

put the oil in it see if it helps or fixes it.
I thought you did check all the belt/pulleys already.. that is the easy part.

 

[TheDurk]

Welp, tried this and it squealed like Jim Carrey in Dumb-n-dumber when he asked "Wanna hear the most annoying noise in the world??"

Little Ceaser: I do not know if the idler pulley had ever been changed....would that explain cold compressor seize? I know it's the belt squealing over an AC clutch pulley that does not initially rotate until warm...just not sure what to do. I guess I could put half a can of R-134 with some oil & see if that helps. If no luck, new OEM compressor & drier goes in. I'll report back results when I get a round tuit. Thanks gang! :beer:

If it really is that your compressor has seized, or semi-seized, it has likely grenaded little pieces of metal and plastic though the system. It is recommended to do a full system flush with a compressor change.

 

[JoT4R]

A little late to the party but did the oil end up fixing the god awful squeal or did you end up replacing the compressor?

-Jo