Joe 121

Thanks Jacob, I'm a little behind with my responses. I ordered the part referenced in this video, just haven't had time to install it.

I got it all back together and it appears to be working. On to the next problem. I have 50 degree air coming from the passenger's side duct and 70 degree air coming from the driver's side duct. Score one for the dual zones. I believe the next step is to pull apart the instrument panel to get access to the Air Distributor Case. At least I don't have to pull out the entire HVAC module. I would appreciate any input from anyone familiar with this particular device. Also, can anyone direct me to GM document on expected Hi and Lo side gauge readings? The internet has plenty of opinions that don't necessary agree with each other.

I know this may sound obvious, but have you checked your cabin filter lately?

I have a 2014 Sierra 5.3L (same truck) with 175K. With the exception of replacing the transmission and maybe the condenser, I've only had to cover the cost of normal maintenance (brakes, oil, filters, plugs, antifreeze, etc). I did have a problem with a broken seat belt which was covered under warranty. I have not seen any major problems with the engine (I replaced 1 ignition coil). I did do what I could to lower the operating temperature of the engine (lower temp on the thermostat and removed the thermostat on the transmission) In the last 10 years, I've done the maintenance as recommended and the truck has been reliable for me. As for me, I'd keep the 2014

I just spoke to AC Delco support. AC Delco Gold is for aftermarket parts, not original equipment. All she could tell me is that she could find several notes from dealers regarding 'fitment issues' for this part number. She couldn't tell me what the issues are, for that I would need to speak to a dealer. She also couldn't give me a part number for the AC Delco Gold Drier assembly I went to the AC Delco website, but, I keep getting 'There has been an unexpected error, please try again later. when I try try shop the GM Parts Store.

As part of replacing my Compressor, I ordered a drier assembly. What I fount was that the GM receiver drier assembly didn't fit into the tube on the condenser. Turns out the tube on my condenser is 14 1/2 inches long and the drier assembly is 17 1/2 inches long. In 2021, I couldn't find the leak and took it to a shop I had done business with in the past. They found the condenser was leaking (big surprise). I told them to go ahead and replace it. He did and everything was fine. It would appear he got an aftermarket part that fit, but all he know is he got it from a local parts supplier. When I found a replacement AC Delco condenser online for $170, I ordered it. The part was advertised as ACDelco Gold 15-63889 (19383805) Air Conditioning Condenser with Automatic Transmission Oil Cooler It didn't indicate it came with the drier, But I already had one. It came in a box with an official looking 'AC Delco Professional' label and the condenser had an 18 inch tube to hold the desiccant. I'm all set. This is where I got myself in trouble When I went to install the drier, I found a plastic plug held in place with a snap ring. I removed the snap ring but I couldn't pull out the plug. I finally got it out with help from a slide hammer and found it had 2 green o rings holding it in place. In the tube was a Desiccant bag. Here is my problem: I destroyed the plastic plug by using the slide hammer. There are no threads in the tube to allow me to install the GM Drier assembly. Does anybody have idea where I can find a drier assembly with just a plastic plug and no threads? Should I have been concerned when I received a box that had been opened and resealed with official online marketer brand tape?

@CamGTPThank you, this is what i needed to know. From what you are saying the system is working as designed. Now on to the next problem

Put it in tow mode and got out on the highway. It mostly stayed between 181 and 183. It did jump to 190 when I accelerated from 60 to 70 and got the RPM up to 4K for a few seconds. It recovered quickly. This was all with the A/C on. I could push the RPMs up but I really don't know what to expect at this level of tracking the temp. Anyone have any suggestions? I've convinced myself it was the thermostat and the A/C was a red herring. Next is to figure out why I'm only getting down to mid 60s when others are reporting A/C in the 50s.

I replaced the water pump as planned. The old one did not show any signs of failure that I could see, but it has 175K+ miles, so it's gone. The old antifreeze looked good to me, nice and pink. I installed the Mishimoto 180 thermostat and put it all back together. According to my scanner, with the AC on, it is running between 181 and 183 in the city (500 to 1.5K RPM). If I hit the throttle (up to 3K RPM), it will climb to 190 and then go back down (about half a minute). Maybe twice in a half of an hour, it did climb to 190 without going above 1.5K, but it didn't stay there vary long. The A/C stayed in the middle 60s, but I wasn't driving very long (89 degrees with Humidity near 80%). I have no experience with tracking the temperature at this level, so I have no idea what to expect. I didn't have time to take it out on the highway today as my good friend Debbie is coming to visit tomorrow morning and I need to get the house ready for her.

@Homewrecker007Thanks, that was helpful

@mikeyk101I checked the condenser for damage/blockage. It looks good from the front. To me, it's acting like a stuck thermostat or a broken water pump. Now I don't if water pumps still loose their impellers anymore, but I have seen it in the past (distant past). It's also possible for the thermostat (even if it's factory) to be stuck partially open. I won't know until I open it up. the Parts I've ordered should be here by this weekend. What I don't understand is why my AC is intermittently blowing hot air. I can't think of a reason these problems might be related, except that they appeared to have started about the same time. While I have your attention, can somebody explain to me why I can buy 1lb cans of 134A, but I can't get a 20lb cylinder? Those 1lb cans waste more freon than anything else. Maybe I just don't know how to suck all the freon out of them. I'm still using a scale and the compressor to charge a system.

@Homewrecker007That makes much more sense. Back in the old days, I lived in Ohio. I had this great idea that I could run my 70 Barracuda without any thermostat at all. I didn't make it past November. @mikeyk101It's that Cadillac thermostat that I have installed right now. I didn't understand until recently why the temp gauge continued to show 210 degrees. 50K miles later, I think that is what my problem is. I had the truck out today with the scanner plugged in. I could see the temperature changing as I drove. I had to quit when I couldn't get the temp below 236 even with the AC off. I think that is telling me the temp sensor is working, but it won't hurt to replace it anyway. I saw this question asked before (I think it was Grumpy Bear), but I didn't see an answer. Does anyone have a part number for the 180 thermostat in the housing?

@Homewrecker007160 thermostat seem kind of cold to me. That website doesn't show any other options. How do you get by in those Ohio winters?

I've got a problem with my 2014 Sierra 5.3L. I live in Florida where the temperatures are in the high 90s this time of year and the humidity reaches up into the 90s as well. It began about a week ago when I noticed the AC wouldn't blow cold on occasion. The gauges indicated the compressor was functioning properly and the temperature inside the cab (at the time I checked) was in the high 60s. I left the thermometer in the vent and found there were times when I was driving that it was blowing air in the 80s. I was on my way to Tampa on Friday (I75) and I was angry that the AC was blowing hot again. The idiot gauge on the dash was hovering just above 210. A message popped up stating that the ECM was going to shut off my AC because the engine was overheating. The idiot gauge was now halfway between 210 and 260 (235?). I pushed the button to turn off the AC and I could see the needle drop back down to 210 almost immediately. After a minute, I turned the AC back on (it was actually blowing cold air) and the gauge stayed at 210 (with the AC on). The outside temperature (according to the dashboard) was 101. The next time I pulled out to pass, the temperature gauge began to climb back up. I switched off the AC again and the needle dropped back down without me taking my foot off the gas. I made the 200 mile trip by cycling the AC off and on traveling between 65 and 70 MPH. When I stopped at my destination, I could hear the radiator fans blowing on high. After it cooled, I checked the radiator (overflow reservoir) was full. Both Fans came on low speed after a minute when I started it back up. The trip home on Sunday was the same. I made it by cycling the AC off and on. It only seemed to have a problem when I accelerated to pass and dropped down when I turned off the AC. The outside temperature was in the low 90s. I have made this trip many times in the past without problem under what I am certain are the same conditions. There were no new trouble codes. I had expected to see something related to the message threatening to shut off the AC. But the only codes I found complained about a burned out bulb at the license plate and some low voltages in the radio/amplifier. There is no noise (that I can hear) or any signs of a leak around the water pump. The truck is 10 years old. I put all 170K+ miles on it myself. I have replaced the transmission and the AC condenser over the years. The trans thermostat has been removed. Around 120K, I flushed the radiator, replaced all the hoses, replaced the thermostat with the Cadillac one (194?) and installed a new temperature sensor. Last oil change (maybe 1K miles ago), I started using that Valvoline 5W30 Restore and Protect. The oil pressure gauge (for what it's worth) shows a solid 40 and the oil level is full. I bought a new water pump and I am looking for a 180 thermostat and temp sending unit. I understand that by turning the AC off, I was significantly lowering the temperature entering the front of the radiator, but I am hoping someone can help me understand what was causing the AC output temp to climb in relation to the engine temp or is that not true? Did the ECM shut down the compressor without turning off the light on the dash? If the compressor was already off, why did my pressing the AC button (to turn it off) have an immediate affect on the temp gauge? The AC was blowing hot air off and on at least a week before this trip. It wasn't until I was on the highway that I found what appears to me to be some kind of relationship.

Just got my truck back from the dealer. The new seat belt tensioner is installed. The seat belt appears to work as advertised and zero charge to me. I can't ask for anything more.