JJ291

A buddy of mine is on some hard times. The other day he said he started his car and heard a pop and his AC won't work now. I put some gauges on it and it showed about 90 psig on both sides with the AC off and 100 psig on the high side with the AC on but the low side immediately plunged toward zero. I shut it off before it drew a vacuum. My first impression was that the TXV is dorked up and his PSV blew which was the loud pop. The unit sounds fine otherwise - no grinding metal or strange sounds in the compressor.

I hate to buy him things he doesn't need and do the work only to find out I was wrong so looking for other opinions. Thanks.

ezone

7th gen car?

Add freon and see if pressures come up to normal?



If the safety valve popped off there would have been a cloud of freon and some stink from the PAG oil, and there should be some evidence of refrigerant oil around the area of the safety valve and wherever direction it is pointed.

WHY would it pop the valve off?
Radiator/condensor fan inop?
Compressor stuck on (clutch relay)?



If it did not actually blow the safety valve, then you might assume the freon wasn't lost, there's an internal blockage somewhere causing the low side to go into a vacuum, and start feeling for where the big temperature change in the system occurs. Clogged condensor? Clogged drier? Stuck TXV?

Due to the location of the high side service port, you could have a blockage in the condenser yet not see extreme pressure on the gauges. Feel temperatures of the lines and condensor to get more of the story.

BTDT plugged up condensor that may have been due to a compressor failure, the compressor still pumped and had enough high side pressure to lug the engine, but the gauge did not show it do to being downstream of the blockage. Compressor discharge hose and pipe screaming hot, and outlet pipe from condensor was cold.

JJ291

Alright, fine! I'm busted! [tears] It's a CRV! 'The worst part is I never learned to read'! Kidding.

It is a CRV... but it's hard to go elsewhere for help when I know you're on here.

When I saw the unit start to hit zero I shut it off because I was afraid of pulling vacuum.

- I will add freon and see what happens
- I thought maybe it was the safety valve because he said he heard a loud "pop" - I will check to see if there is any freon evidence around the valve (he did not mention any hissing when I asked him)
- I will try and run the unit and see if I can identify a temperature difference anywhere in the system
- I will check the fan also - the compressor clutch engaged and the compressor sounded normal to me

If it starts to hit zero should I turn it off or keep running and complete the inspection?

ezone

FerGawdSakes at least let me know what I'm dealing with, so I can put on the right thinking cap at the start of my thinking!

I use this line all the time. I work for a dealer, I must not be able to read.

Also, I like to use the "I'm old, I don't remember" line when other mechanics bug me for free fixes. Read the service manual! Pay your own dues, dammit.
What YEAR? HOLY POOP, what year is the CRV????

And how many miles are on it?

JJ291

I can only imagine what you have to deal with - especially in the post millennial world..."hey ezone, what app do I download so I can be a mechanic like you?" I get some of that at my job also.

It's a 2008 with 179,000 miles. Unfortunately, his ex wife's brother's monkey's uncle installed a new compressor in it but given the total price he paid there's no way it was OEM.

I don't want to waste your time and I can get him over this weekend and take a better look. I didn't have much with me except my manifold the night I looked at it.

ezone

Nah, it seems like the young ones just have no desire to do a damn thing, they want to collect a check for standing around and hide when it comes time to do something.
No desire to work, and don't know how to work when they do have to.

And they have little or no supervision in this shop, that doesn't help anything. If I had any authority over other employees, they wo........Uh, I'd probably be the only one left in the shop (if I didn't fire myself too).

Nothing stands out in my mind.

I was thinking if it was an 02-04-- the compressor may grenade, literally.

I'd want to know why it was replaced and how the old compressor failed--- if it actually failed internally it could have sent debris into the condensor.

================================

Meh, someone else already ran it like that for a while, you probably won't kill it.

I'd let it run long enough to check what I need to check. You won't find temp differences unless it's running.
Got a machine to recover and charge by weight?


I don't know that I've heard anyone say the valve pops when it opens, I think it's more like a steam blowoff noise---only with freon.
See what you can see though.