AC broke, but *MAGIC* and now it's fine

Okay so had a weird issue with the AC on my 2020 SR5. When I cranked it up on Thursday, it smelled kinda like wet hay and was giving me an odd hissing noise. Imagine listening to a microphone recording of a can of compressed air leaking inside a metal drum. That's the best I can explain it. Sometimes it sounded like metal scraping metal. Checked the clutch and it was still cutting on and off like normal. No noise inside the hood, only inside the cab. Over the course of Friday, it lost its ability to blow cool air on the passenger side. Went to the dealership Friday afternoon, and they couldn't immediately diagnose. So I scheduled an appointment to come into the dealership later on Tuesday afternoon. Parked it over the holiday weekend. When I cranked it up Tuesday morning the AC clutch wouldn’t even cut on, signaling that it had in fact lost all of its refrigerant as I suggested it was doing to the tech on Friday. The tech confirmed Tuesday afternoon after several hours that the refrigerant was in fact completely empty, but he couldn't find a leak anywhere. I left it overnight so they could continue to attempt a diagnosis as I wanted this repaired under warranty instead of forking over the $200+ bucks they told me I was gonna have to pay for an AC recharge if they couldn't find a warrantable default. After a whole day of supposed testing and such, they tell me they still can't find a leak and that it's holding its refrigerant and blowing icicles. They're going to cover it under warranty after I basically argued for 5 minutes, but how the heck could it be venting refrigerant and then suddenly just not do it anymore? Anybody else had similar issues? I know some folks have posted about bad seals and such, but I couldn't find any posts that seemed to match my problem.

TLDR: the AC broke and vented all it's refrigerant, and then somehow it's fine and there's no leak.

 

Supposedly, the a/c is programmed to run uncommanded every once in a while to keep everything lubed. So, that would make your situation even muddier. I have no source to back this up though.

The only thing that you can do is see what happens down the road. With it covered under warranty once, it should make it easier if it happens again.

 

Based on the other threads I’ve read, it seems like the main thing I want to do to make sure this thing will get taken care of under warranty in the future is to make sure I get the pressure readings from an AC Manifold test. Am I missing anything else I should be watching out for? I’m concerned this is gonna be a squirrel I’ll be constantly chasing in the future.

 

I appreciate the specificty of sound description lol. That's a strange one. Maybe o-ring related or something.

 

Maybe a shitty dealership, maybe a service writer that can't communicate what the techs told them..

 

Did they put dye in with the recharge?
If it happens again, it would be easy to see where it's coming from.

Most likely a compressor bearing seal.

 

The AC guy who was working on it mumbled something about not being able to use dye anymore with the system. Not sure if he meant the new refrigerant, their machine, or was just full of it.

 

Refrigerant leaks don't just fix themselves. That odd noise from inside was probably the Thermal Expansion Valve moaning due to the low refrigerant charge.

*from dealership experience. I bet the Evaporator Core is leaking. It's a pain to replace and the tech will take a beating on warranty labor. So the Tech just wants to keep recharging the system to kick the can down the road. Then youll be out on warranty and it becomes customer pay.

Look for Dye around the A/C drain tube on the firewall.

 

×5

 

Okay with all the threads on 3rd gen AC problems I have no idea why this hasn’t been mentioned yet but it’s likely the issue with every AC leak in most of the third gen’s on here, except for the few unlucky ones who’s evaporator core is leaking (as mentioned above), but those are quite rare and easy to spot due to oil coming out the drain.

**According to a friend who’s a tech at the local dealer, when I whined to him about loosing my AC he told me he could tell me without even looking because he does so many and sure enough he was right.

Tacoma’s with the current 1234YF systems develop leaks at the top port of the A/C condenser where the high pressure line goes into the condenser. What happens is galvanic corrosion builds up around the fitting causing deterioration of the O-ring thus loosing the seal.

The solution is to vacuum the system, remove and clean the fitting, replace o-ring, putt it all back together and recharge, just for the galvanic corrosion to happen again in a year or so. It’s a poor system design.

 

Correction, it’s the high pressure line going into the condenser, and here’s my evidence.

 

Good to know… Thanks for sharing that info.

 

Thanks for the help. I'll be sure to talk to them about this when I go in. I have a feeling they won't want to have anything more to do with it until it all leaks out again though.

 

This alone tells me they're shit.

I have a vehicle under warranty, the AC doesn't work, there's your default.

Crisp new dollar bill says they just recharged it to get you out the door and it will be dead again ASAP.

Find another service department.

 

Go ahead and make an appointment for next month. You'll need it.

 

My truck is far out of warranty and the cost to get the dealership to do the service is absolutely ridiculous. My temporary solution is a 50$ can of 1234YF recharge from the local auto Napa. This of course will leak back out since the leak is still present but it’s been a few weeks with no loss in cooling yet and I only used half of that can. There’s also the risk of loosing enough oil to cause damage to the compressor but my truck isn’t my daily so I’m willing to take the risk for now.

I’m waiting on the company I work for to suck it up and buy a 1234YF machine so that I can do the service myself. We have a 134a but our new fleet is all 1234YF and they just figured out their machines aren’t compatible so they don’t have a choice.

 

Okay so, I don’t think it’s fixed at all. I’ll concede that it was TECHNICALLY blowing cooler than when I dropped it off, but it doesn’t seem to be performing right and all. And it sounds like this: https://youtube.com/shorts/t_RfJaG7dCY?feature=share

 

That sure sounds like the Compressor clutch

 

no it does not, I had the exact same sound coming out of my truck and as stated above:

That odd noise from inside was probably the Thermal Expansion Valve moaning due to the low refrigerant charge.

your refrigerant is still to low, either get them to top it back up or find and fix the leak. When I refilled mine with a can from Napa that sound went away and my balls are being chilled again.

 

It's definitely lost more refrigerant by this morning. I'm waiting on a call back from their service manager to see what they're willing to do about it for me.