Not sure why they can't figure it out for you. They aren't very complicated systems.

And them using the excuse that it's a new type of system that they aren't used to is utter BS. In 2017 they went to r-1234yf instead of r-134a. The systems are the same operation wise as they have basically always been, just the refrigerant changed. However, being a dealer, and having the r-1234yf out for several years now, they absolutely should know how to handle it given it's in all the vehicles.

But perhaps try a different dealer if they can't help.

 

Definitely go to another Chevy or GMC dealership if they are still clueless after taking the dash apart.

 

If it has that big of a leak they should be able to find it if they are any good at all.
Sounds like a bs excuse to me too that they aren't used to working on that year ac, especially a dealer. They should have all the tools and resources necessary to solve the issue.
I don't know that I would trust that place to start tearing apart the dash when they can't even find an ac leak. Is there another dealer you can take it to for a second opinion before they start taking apart the dash?

 

Agree with Terry...
Another dealer....
And before they take the dash apart!

 

^^^ This.

 

granted its a little older but we replaced almost the entire AC system, lines, compressor condenser, seals and all in my dads truck and vacuumed down and charged up with no prior experience. Its not hard at all

 

So we got an update for you guys... You're probably going to laugh, but they claim they fixed it this afternoon. I picked it up at about 2:00 p.m., and the air conditioning worked at the time. By about 5:00 p.m. I got back in the truck and tried driving to a location about 20 minutes away. It got a little warm inside the truck, so naturally, I tried to turn on the air conditioning. I heard a hissing noise and a strange smell came through the cab of the truck that smelled like refrigerant. Believe you're not the air coming out of the fence was NOT COLD! I'm at a complete loss, five attempts to fix the air conditioning and it's still broken. I guess I need to go to another dealer, which is a pain because I live in Maine and dealers are few and far between.

Truly the hard part is to find a dealer willing to give you a loaner truck while they attempt to fix this. My local dealer could only give me this tiny loaner subcompact Buick that tops out at 85 mph with the pedal on the rug. I need the truck for work, and unfortunately a tiny Buick does not replace it.

 

Call the Chevrolet (GM) Executive Office 313-667-7153 and tell them what is going on. This office is above Chevrolet/GM Customer Service and the people in this office can and do work miracles. I've used them twice and was more than pleased with their results, and they do call you back when they say they will. Problems get resolved in days, not weeks,

 

I just did this. Thank you for the suggestion. The representative said they will be getting engineering involved to figure out the problem, and also find me a truck to have as a loaner.

 

That is horrible. I hope you get your truck fixed on the next visit wherever you go.

 

So we got an update for you guys... You're probably going to laugh, but they claim they fixed it this afternoon. I picked it up at about 2:00 p.m., and the air conditioning worked at the time. By about 5:00 p.m. I got back in the truck and tried driving to a location about 20 minutes away. It got a little warm inside the truck, so naturally, I tried to turn on the air conditioning. I heard a hissing noise and a strange smell came through the cab of the truck that smelled like refrigerant. Believe you're not the air coming out of the fence was NOT COLD! I'm at a complete loss, five attempts to fix the air conditioning and it's still broken. I guess I need to go to another dealer, which is a pain because I live in Maine and dealers are few and far between.

Truly the hard part is to find a dealer willing to give you a loaner truck while they attempt to fix this. My local dealer could only give me this tiny loaner subcompact Buick that tops out at 85 mph with the pedal on the rug. I need the truck for work, and unfortunately a tiny Buick does not replace it.

This to me says a clogged low pressure tube. Doesn't sound like they've fully-evacuated the system. They are probably assuming that they depressurized it that a clog of moisture/crud will all come out, not the case. Definitely go to another dealer, don't give up on warranty coverage.

 

Glad to hear they are still responsive. You might now become a "preferred customer" at that dealership and be treated much better from this point on.

 

Any updates? I'm taking my 2018 Sierra in on Wednesday. Blowing warm air. Put gauges on it, and had the low pressure side at 25psi when running full blast. Charged it to 40psi, and blew cold for about a day, then back to warm and down to 22psi. Leak somewhere I do believe.

 

Sorry I didn't see this before, I hope you got your truck fixed. For me it ended up being the evaporator core, they basically disassembled the whole cab to get to it, before doing that they replaced the compressor, condenser and all the lines. GM engineering had to get involved to solve the problem. At the dealer rate it ended up being in excess of $6k of labor and parts, thankfully GM picked up the bill on this one.

They claim it wasn't easy to get their refrigerant sniffer in there because the evaporator is buried in the dash, but the telltale sign that should have given it away I guess was the smell of refrigerant inside the cab. I only smelled it once, because I only picked up the truck soon enough before it all leaked out one time. I would think the techs would have picked up on this, but it is possible that they are nose blind to the refrigerant smell when working with it all day

 

Let them know that this now falls under lemon law rules, and they can either fix it or buy it back, and that you will take a loaner home while they decide what to do. It will likely be fixed by the morning.

 

To clarify, it was fixed. I ended up getting a loaner Doge 2500 while they had my truck.

 

Mine ended up being the condenser. You know the part? Same EXACT one that the 2015-2017 models had so many issues with, but since it wasn't one of those, the repair fell on me. Since 1000 Youtube videos show how easy it is to replace in about 2 hours without pulling the bumper off, and the part is only $140, I figured they'd be able to evacuate it, swap it, recharge, etc. for maybe $500 (R1234yf is way more expensive than R-134a), but I was dead wrong. The book says they have to pull the bumper, etc.. to get to it, and the cost would be $1700. While we were discussing it, a salesman came and told me they'd give me what I paid for it 2 years ago on trade. I called BS, but he wasn't joking.

I had purchased the 2018 2 years prior with 7200 miles on it, but another 52,000 miles on it (odometer was at 59,233 when I pulled into the dealership) and they gave me $44,500 for it towards trade on a new 2021 Silverado RST. I still got the dealer incentives and all rebates, talked them down about $1500 off the MSRP, and they took the broken truck. Sure, they'll fix it a lot cheaper than what they would have charged me, but I felt like I got a steal of a deal. After a 5 year/125K GM warranty (bumper to bumper, 0 deductible - FL law won't let them profit on extended warranties), I still walked out with a new truck and my payment went down over $100/month.

 

I have a 2018 LTZ 6.2 and it’s leaked down to less than half its charge every year since new. 2 different dealers are unable to find my leak.

 

My AC won't blow cold in my 2018 gmc sierra. Can someone tell me what it could be? I was told that it could be the ac compressor pressure sensor/switch.

 

It could be a lot of things

 

Could you give me a suggestion on what it could be? The compressor comes on, it just won't get cold. There is no condensation around the lines, so it's not low in freon. That's why I'm thinking it could be the sensor or switch.

 

Blend door?

 

What's that?

 

The blend door is actually fine.

 

So you've verified that the actuator is moving the blend door back and forth, and that the post the actuator rotates is still attached to the door?

After that, assuming the fan is working, would be checking if there is any debris on the evaporator in the hvac ducting (should be able to use an inspection camera to check this, perhaps through the opening where the fan mounts afte removing it).