2010 Tahoe AC HELP!!

[lowcomet]

I had a major failure of my original ac compressor. Replaced condensor, orifice tube, expansion valve (rear air), rear evaporator, drier, hard line from condensor with muffler, pressure switch, high and low side valves, compressor and did a thorough flush on what was re-used in the system. 11oz of Pag through the system, deep vacuum, 2.5lbs freon and new belt.

Ordered a NEW 4seasons brand ac compressor.

Don't get me wrong. ICE cold air.
Compressor noisy as all get out!
Very aggravating! Seems like AC compressor are hit and miss.

Does anyone know of any particular brand AC compressor that is consistently good quality?

I haven't read much good on any brand including acdelco.

 

[sumo]

I work on cars for a living. Whenever a customer chooses to use an aftermarket compressor, I usually see it back in the future. Weather it’s a customer car or a used car I find going with a oem compressor is always the better option when it comes to ac components.

 

[lowcomet]

I work on cars for a living. Whenever a customer chooses to use an aftermarket compressor, I usually see it back in the future. Weather it’s a customer car or a used car I find going with a oem compressor is always the better option when it comes to ac components.

So in my case that would be an ACDelco brand, correct?

 

[sumo]

So in my case that would be an ACDelco brand, correct?

Yep ac delco

 

[lowcomet]

So I installed an original Denso unit, replaced what oil was lost, vacuumed system for an hour. Its was 70 degrees fareinheit ambient temp and pulled 29in of mercury during vaccum. Let sit for another hour to verify no leaks.

As mentioned before, everything was replaced and flushed when the four season brand compressor went on. The four seasons brand came off a week later due to being noisey and immediately replaced with the Denso unit, orifice checked and then vaccummed down.

Now my gripe is now that its 90 degrees ambient temp today, vent temp reach a measly 50-60 degrees at idle and mid 40s while driving but not without the occasional cycle and temp fluctuation. and just generally slow to get cold.

I hooked up my gauges at idle while vent temp were mid 50s and read 35 low side and 125 high side.

Now to me the high side seems a bit low given the ambient air temps.

Am I possibly overcharged? Another bad compressor? too much moisture and air in the system? A flapper not functioning properly allowing heat to be pulled from heater core? (both sides read same vent temps)

I am really at a loss and frustrated, any AC experts please HELP ME!! Thank Yall!

 

[sumo]

That sounds right. Our interiors are huge and takes time to cool down. Make sure you’re on recirculate mode and not fresh air. Recirculate will keep pulling the air inside the cabin and make it cooler every time it passes through the blower as supposed to outside air that’s hot

 

[lowcomet]

That sounds right. Our interiors are huge and takes time to cool down. Make sure you’re on recirculate mode and not fresh air. Recirculate will keep pulling the air inside the cabin and make it cooler every time it passes through the blower as supposed to outside air that’s hot

Definitely on recirc mode. How big the interior space is what I had lerking in the back of my head but I've never had anything that big with front and rear air. My reg cab truck vents gets cold seemingly instant with much smaller cab space and guess I'm used to that.

Something else rollin in the noggin is the truck requires 2.5lbs of freon, 11oz of oil. Is the oil in addition to the freon or is it 2.5lbs of freon including the oil?

 

[sumo]

Definitely on recirc mode. How big the interior space is what I had lerking in the back of my head but I've never had anything that big with front and rear air. My reg cab truck vents gets cold seemingly instant with much smaller cab space and guess I'm used to that.

Something else rollin in the noggin is the truck requires 2.5lbs of freon, 11oz of oil. Is the oil in addition to the freon or is it 2.5lbs of freon including the oil?

All you need is 2.5lbs. The compressor usually comes profiled with the 11 oz pag so you don’t need to account for that.

 

[lowcomet]

All you need is 2.5lbs. The compressor usually comes profiled with the 11 oz pag so you don’t need to account for that.

Mine came with 3 oz prefilled but I made sure after flushing that the system got its full 11ozs.

 

[sumo]

Mine came with 3 oz prefilled but I made sure after flushing that the system got its full 11ozs.

Here’s a chart off all data

 

[lowcomet]

Here’s a chart off all data

View attachment 199387

Awesome info, thank you! Thanks for all your help but really weird that states 8oz for denso replacement. Mine came with explicit instructions it came pre-filled with 3ozs.

 

[gpracer1]

2.5 lbs of 134a is no matter how much oil it holds. Make sure the air is on recirc and on high speed blower with temp set to 60 or lowest setting front and rear, both driver and passenger.
How are you charging the system? Big 25 lb bottle or little cans? Plain 134a or some mix crap superdupericecoldarcticblend ? Purge the charge line to remove air before opening gauge valve. Add ounces per can into lbs correctly.....etc. It actually sounds slightly undercharged..assuming the compressor is not weak...what about at 1200 rpms?

 

[gpracer1]

Just for my future reference I just hooked the gauges to my 13 LTZ with front and rear on high blower recirculating.
Ambient temps 92 degrees, ac running for 10 min.
Low side 36.6, high side 209.3 with cooling fans on low.
Reved engine for a few seconds to kick the high fans on and back to idle, 34.4 low and 188.3 high. Cold air temp at 45and 43 degrees.
At 1200 rpm low 27.8 and high side 253.9 with cooling fans on high. Cold air blowing at 38 degrees on high blower.
Note I have the enhanced cooling package.
Hope that helps.

 

[lowcomet]

Just for my future reference I just hooked the gauges to my 13 LTZ with front and rear on high blower recirculating.
Ambient temps 92 degrees, ac running for 10 min.
Low side 36.6, high side 209.3 with cooling fans on low.
Reved engine for a few seconds to kick the high fans on and back to idle, 34.4 low and 188.3 high. Cold air temp at 45and 43 degrees.
At 1200 rpm low 27.8 and high side 253.9 with cooling fans on high. Cold air blowing at 38 degrees on high blower.
Note I have the enhanced cooling package.
Hope that helps.

I'm using cans of pure r134a. always purge the line and account for loss while purging, while on the scale between can changes and converting oz to pounds. I'm not sure at 1200rpm. But I can tell you I dont see those kinds of pressures on the high side. I was seeing around 125 high side idling and not much change when reving to 1000rpm. This Tahoe was originally destined for upstate NY. I live in Missouri where during summer months temps and humidty is high. What is this enhanced cooling package you speak of? Is it a specific RPO code for say trucks that stayed South?

 

[gpracer1]

I'm using cans of pure r134a. always purge the line and account for loss while purging, while on the scale between can changes and converting oz to pounds. I'm not sure at 1200rpm. But I can tell you I dont see those kinds of pressures on the high side. I was seeing around 125 high side idling and not much change when reving to 1000rpm. This Tahoe was originally destined for upstate NY. I live in Missouri where during summer months temps and humidty is high. What is this enhanced cooling package you speak of? Is it a specific RPO code for say trucks that stayed South?

K5L is the RPO code. You will know when your fans go to high, they roar loudly and you can feel it walking by the front of the truck.
Your high side is too low. You were saying it was 90 degrees outside? At 90 ambient your high side should be around 170-220. Sounds like either compressor is not working properly, possible restriction in condenser as in metal (check for high line to be hot all the way to the gauge port, after that it should be cold at orifice) , possible rear AC expansion valve stuck open, or undercharged system.
When you rev the engine the high side should go up and the low side down. If it doesnt then compressor is bad.
Idle will always be the warmest so mid 40s is good on high blower. At highway speed mine blows high 30s around 38.

At this point I would add a few ounces of 134 at a time and watch the pressures, if undercharged your low side will stay almost the same and the high side will go up......temps should drop.

 

[lowcomet]

K5L is the RPO code. You will know when your fans go to high, they roar loudly and you can feel it walking by the front of the truck.
Your high side is too low. You were saying it was 90 degrees outside? At 90 ambient your high side should be around 170-220. Sounds like either compressor is not working properly, possible restriction in condenser as in metal (check for high line to be hot all the way to the gauge port, after that it should be cold at orifice) , possible rear AC expansion valve stuck open, or undercharged system.
When you rev the engine the high side should go up and the low side down. If it doesnt then compressor is bad.
Idle will always be the warmest so mid 40s is good on high blower. At highway speed mine blows high 30s around 38.

At this point I would add a few ounces of 134 at a time and watch the pressures, if undercharged your low side will stay almost the same and the high side will go up......temps should drop.

Expansion valve, condensor, drier, orifice was new at time of compressor replacement, everything else was flushed. yes 90 ambient. I tried adding a small amount with small change in high side pressure. if memory serves me correctly it was around 150 high side after adding a little. never saw much fluctuation with high side pressure. Ill be sure to check the liquid line to make sure its getting hot. low side, past the orifice sweats like crazy and cold. When i get a chance I'll hook my gauges up again and see where I'm at on pressures.

 

[lowcomet]

K5L is the RPO code. You will know when your fans go to high, they roar loudly and you can feel it walking by the front of the truck.
Your high side is too low. You were saying it was 90 degrees outside? At 90 ambient your high side should be around 170-220. Sounds like either compressor is not working properly, possible restriction in condenser as in metal (check for high line to be hot all the way to the gauge port, after that it should be cold at orifice) , possible rear AC expansion valve stuck open, or undercharged system.
When you rev the engine the high side should go up and the low side down. If it doesnt then compressor is bad.
Idle will always be the warmest so mid 40s is good on high blower. At highway speed mine blows high 30s around 38.

At this point I would add a few ounces of 134 at a time and watch the pressures, if undercharged your low side will stay almost the same and the high side will go up......temps should drop.

So im currently looking at my pressures and its 96 ambient temp outside. low pressure is 43 and high pressure is 30. Vent temps at idle are 60. High side line is nice and toasty and past orifice tube everything is sweating. if i hold the revs around 1200 rpm the fans kick in high gear and high side only goes between 30 and 35 i have the rpo code k5l as well. Im at my wits end. This is compressor #3. Sounds like its failing to me. What do you think?

 

[lowcomet]

Screw it! I just ordered another new compressor!

 

[gpracer1]

Screw it! I just ordered another new compressor!

So im currently looking at my pressures and its 96 ambient temp outside. low pressure is 43 and high pressure is 30. Vent temps at idle are 60. High side line is nice and toasty and past orifice tube everything is sweating. if i hold the revs around 1200 rpm the fans kick in high gear and high side only goes between 30 and 35 i have the rpo code k5l as well. Im at my wits end. This is compressor #3. Sounds like its failing to me. What do you think?

High side is 30-35???
I can only assume you mean 130-135 or you have a serious problem.

 

[gpracer1]

Any new news?