AC Compressor Issue/Ac compressor screaming- '01 Tacoma

Hello All,

A few years ago the tacomaworld forums helped me fix a troubling intermittent issues (https://www.tacomaworld.com/threads/recharging-system-issue.555600/). I'm hoping you guys can steer me in the right direction and help me keep this truck in top service without breaking the bank!

Issue:
A few days ago I turned on the AC and was greeted by an absolutely deafening AC screech. Turning the AC off would immediately stop the noise; however leaving it on the noise would stop on its own within five seconds. The scream would be gone for another 1-5 minutes of drive time before it, inevitably, returned. I kept AC to a minimum however the screech is more and more prevalent.

Background:
Last year the AC compressor died on me (hence I'm very familiar with this sound) and I replaced it myself with an OEM refurbished (full evap of system, ac compressor replace, receiver/dryer replace, recommendations for pag oil levels, the works.) 01 Toyota Tacoma, 150k miles. I also replaced all the tensioner pullies, as well as two years ago the harmonic balancer and alternator/belts/etc. ​

Investigation:
Ac belt turns fine turning on, tension looks fine, turning the AC clutch with my hand (engine off) has some resistance but not so much that my hand cannot turn it several revolutions. Cranking and AC turned on, watching the AC, the clutch starts to turn/stop with loud screaming. It also appears that the scream is non stopping now, however I will admit I was hesitant to continue to let it run for more than 15 seconds.


Questions:
After some online research and forum threads, and not wanting to go through another AC job, it appears it may be just the clutch? It also appears with SOME ACs I may be able to replace the clutch without removing the compressor or evaping the systeming.
1. Does anyone know, for certain, if I can start trying to pull that clutch apart without spraying the Freon everywhere?
2. Does it sound like the clutch or something else?
3. Thoughts?


Thanks guys. In hindsight theres lots of great information on these forums and I should have posted the AC compressor replace for other folks. As I could not find it here, if replacing the clutch solves the problem, I'll try to post the steps for this fix for anyone searching in the future.

Sorry for the tl;dr just trying to knock out extra questions with one post. As always THANK YOU for any assistance and advice you can provide!

 

if the screech is only when the magnetic clutch is engaged I would check belt tension first and if that is ok spray some a bit of carb cleaner, brake cleaner on the belt to see if the screech gets louder, goes away or does nothing different. We are trying to determine if this is a belt issue, a magnetic clutch issue or a compressor issue. Look at the air gap between the magnetic coupler and look at the condition of the faces of the coupler too. I want to say the air gap is .020 to .025 inches IIRC. Yes the clutch can be pulled off and replaced depending on your selection of tools/snap ring pliers. It might be necessary to take the compressor off its mount and swing it or twist it so that you can get at what you need to get at. The 4 cyls are a little easier that the V6 but they all require patience. I this was me doing the job and it was more than 2 years since a coolant change, I would pull the radiator and 2'fer it, now you have LOTS of room.

 

Eh there was a coolant change last year when I did the AC job. If you're going to swap the AC condenser might as well give yourself some more space! Then again, swapping coolant is much friendlier beating your knuckles up and potentially working around blind corners! GREAT to know I could potentially fix this without a trip to the garage for evap and trying to rent AC gauges and pumps from the shops!

Belt tension seems fine to me to the best of my ability. Has small play and then a few extra turns on the tensioner bolt. When I crank the vehicle (AC off) the belt is spinning along without any delay as well as the AC compressor's pully. Then, turning with the ac compressor and producing the noise, the belt starts to stop and go its revolutions every two seconds with a major delay. This is also when the center portion and front face of the AC compressor starts to turn with the belt (I'm assuming this is the AC clutch assembly) also in a stop and go fashion. Center portion referred to can be identified as just below (towards the bottom of the picture) my finger.


The airgap looks fine to me (estimating something in the 10ths of an inch). The above picture is from the bottom looking up. Below picture is bottom down.


annnd finally the face, with an almost shiny reflection of my phone case.



I don't see anything that's jumping out at me. Let me know if you see anything.


Also, upon recommendation, I can always tighten the belt a fair ways more/crank down on it and see if it will drag it along and stop the noise. As for the brank cleaner on the belt, just spray it on there and see if that affects the noise in anyway? Yeah I can, just to clarify, we are talking about the belt and not any part of the AC correct?

 

You need to check belt tension first as stated. If it persists you have an issue with the compressor. What brand compressor did you purchase? If it was anything but Denso that is the wrong answer and if the issue persists replace with a quality equal to OE or OE specific part.

 

Sorry for the confusion and thanks for jumping in guys. Yes the belt tension is good, I'll admit I eyeballed it verses breaking out a ruler. Give me a while and I'll confirm definitively there is .5" play.

As for the actual part I cannot remember the name brand. I know advanced or autozone, whichever one, stated it was an OEM refurbished. I insisted on OEM and they worked it out to order and ship. And wouldn't you know it I remember finally throwing away the receipt a few months ago while cleaning out the old top drawer.

Thoughts on compressor vs compressor clutch? Other thoughts?

EDIT- Broke out the measuring tape. I'm around .5" at a centerpoint of slack on the belt.

 

My sons and 4runner made a crazy screeching noise and it ended up being over filled. My understanding is there pretty particular on refrigerant levels.
Aslo similar symptoms.

 

Thanks for the suggestion chrslefty! Unfortunately I haven't added any since replacing it last year with no issues. Possible that I have a leak somewhere I guess, but it was spitting out cold air a few days ago when the problem started.