A/C issues

[ECaseyP]

I've had this 14 tahoe a little over a month now and when it is hot out the AC takes a long time before it starts feeling like it's colling off. It takes at least 20 minutes before it feels like the air coming from the vents is cold. I haven't checked the actual temp coming out of the vents yet. I hooked up AC gauges to it a few weeks ago and everything looked good on the readings. Low side was about 50-55 and high side was around 250-275. The temp was 90 degrees outside, so it wasn't as hot as it has been here lately. We've been 103-107 the past week.

A guy at worked noticed this morning that my AC drain is producing a lot of condensation, both front and rear drains. I haven't looked for one yet, but is there a cain filter in a 14 LT Tahoe? Is there anything else I can check before taking it to a shop to look at it? I don't have time to fix it myself or I would. I used to be a diesel mechanic for almost 18 years and a few years back I started school and changed careers last year. Thanks for the help.

 

[Geotrash]

I've had this 14 tahoe a little over a month now and when it is hot out the AC takes a long time before it starts feeling like it's colling off. It takes at least 20 minutes before it feels like the air coming from the vents is cold. I haven't checked the actual temp coming out of the vents yet. I hooked up AC gauges to it a few weeks ago and everything looked good on the readings. Low side was about 50-55 and high side was around 250-275. The temp was 90 degrees outside, so it wasn't as hot as it has been here lately. We've been 103-107 the past week.

A guy at worked noticed this morning that my AC drain is producing a lot of condensation, both front and rear drains. I haven't looked for one yet, but is there a cain filter in a 14 LT Tahoe? Is there anything else I can check before taking it to a shop to look at it? I don't have time to fix it myself or I would. I used to be a diesel mechanic for almost 18 years and a few years back I started school and changed careers last year. Thanks for the help.

Probably the first thing to do is see if the compressor starts right away after you start the engine first thing in the morning. If the compressor is running then either you don't have enough refrigerant in the system to do the job, the condenser is packed with dirt/debris, or you have an air delivery problem inside the cabin. On these trucks, the blend door actuator can stick partially between heat and cold, so after looking at the things above in the engine compartment, that's the next thing I would look at. You would need a Tech2 to determine the blend door position commanded vs actual position. There is no cabin filter from the factory but there is a cabin filter kit that some folks install, so you can tell by looking at the duct below the dash near the blower fan.

Your pressures seem okay for 90ºF ambient temp but it's possible the actual temperature of the system was higher. In which case your numbers would be a little low. Here is a chart that will help you with making an accurate estimate. If your refrigerant is indeed a little low, then I would spray some soapy water on the high and low side service ports with the dust caps removed. It's common on these trucks for the little Schrader valves to leak after several years.

 

[ECaseyP]

Probably the first thing to do is see if the compressor starts right away after you start the engine first thing in the morning. If the compressor is running then either you don't have enough refrigerant in the system to do the job, the condenser is packed with dirt/debris, or you have an air delivery problem inside the cabin. On these trucks, the blend door actuator can stick partially between heat and cold, so after looking at the things above in the engine compartment, that's the next thing I would look at. You would need a Tech2 to determine the blend door position commanded vs actual position. There is no cabin filter from the factory but there is a cabin filter kit that some folks install, so you can tell by looking at the duct below the dash near the blower fan.

Your pressures look a little low to me for 100ºF ambient temps. Here is a chart that will help you with making an accurate estimate. If your refrigerant is indeed a little low, then I would spray some soapy water on the high and low side service ports with the dust caps removed. It's common on these trucks for the little Schrader valves to leak after several years.

I'll look at the compressor in the morning to see. I'll probably try to look at the pressures again this weekend.

Probably the first thing to do is see if the compressor starts right away after you start the engine first thing in the morning. If the compressor is running then either you don't have enough refrigerant in the system to do the job, the condenser is packed with dirt/debris, or you have an air delivery problem inside the cabin. On these trucks, the blend door actuator can stick partially between heat and cold, so after looking at the things above in the engine compartment, that's the next thing I would look at. You would need a Tech2 to determine the blend door position commanded vs actual position. There is no cabin filter from the factory but there is a cabin filter kit that some folks install, so you can tell by looking at the duct below the dash near the blower fan.

Your pressures look a little low to me for 100ºF ambient temps. Here is a chart that will help you with making an accurate estimate. If your refrigerant is indeed a little low, then I would spray some soapy water on the high and low side service ports with the dust caps removed. It's common on these trucks for the little Schrader valves to leak after several years.

I'll definitely give those a look. I may hook the gauges back up this weekend just to make sure on the pressures.

 

[j91z28d1]

what was the vent temp doing when you got those pressure?

might help to know what the the pressures are when you first start it and vent temp is hot.

if your low side is in the 50s and vents blowing hot for 10mins, that seems like blend doors, there's a reset on the tech 2 but I have read the whole take the cables off for a while and then touch the cables together will cause a reset cycle when you turn the key on. but I can't confirm that actually works.

 

[me88]

there's a reset on the tech 2 but I have read the whole take the cables off for a while and then touch the cables together will cause a reset cycle when you turn the key on. but I can't confirm that actually works.

You can also relearn the blend doors by removing the HVAC/ECAS fuse with the key off, then wait for at least 10 sec. and reinsert it. Start the engine and do not touch the AC controls for at least 40 seconds.

 

[BG1988]

I've had this 14 tahoe a little over a month now and when it is hot out the AC takes a long time before it starts feeling like it's colling off. It takes at least 20 minutes before it feels like the air coming from the vents is cold. I haven't checked the actual temp coming out of the vents yet. I hooked up AC gauges to it a few weeks ago and everything looked good on the readings. Low side was about 50-55 and high side was around 250-275. The temp was 90 degrees outside, so it wasn't as hot as it has been here lately. We've been 103-107 the past week.

A guy at worked noticed this morning that my AC drain is producing a lot of condensation, both front and rear drains. I haven't looked for one yet, but is there a cain filter in a 14 LT Tahoe? Is there anything else I can check before taking it to a shop to look at it? I don't have time to fix it myself or I would. I used to be a diesel mechanic for almost 18 years and a few years back I started school and changed careers last year. Thanks for the help.

check the front condenser to see if it's clogged up with bugs/dirt and the inside one as well(Evaporator coil) these can be clogged and result in poor performance...

distilled water and a tooth brush be gentle

put down a trash bag to keep it clean inside other wise risk of dirtying the interior