2009 AC Cool not Cold

[murdoc]

I had a compressor go bad on me a few months back, so I've been living with no Air Conditioning until I got the money to replace it. Out of an OVER abundance of caution, I replaced everything! The evap core, all three hoses, compressor, expansion valve, and condenser with drier.

When I got the compressor I drained out the factory oil that it came with. It said it came with 4.4 oz. I for sure got 3oz out into a cup, and probably spilled another oz on the ground. I then carefully added new oil mixed with dye. About 3 oz to the compressor and 2 oz to the evap core. ( The new compressor instruction said to add half to the compressor and half to the rest of the system)

I carefully vacuumed down the system and it held at -29 psi for over 12 hours (got distracted by dad duties). Then attached the Freon (yes it was "Freon" brand R-134a) to the system. I purged the line, and then opened the low side and let the can fill the system with the engine off until it equalized. Then started the car and added the rest of that can, and 6 oz from the next can. That should be 18oz total, which is what the system sticker in the engine bay says it needs.

So here's my problem. With the ambient air temp at 83 degrees F, air conditioner on, fan on high, recirculation on. The air in the center vent only measures about 53-55 degrees F. According to the shop manual, it should be around 45 degrees at that ambient temperature.

Since there was some Freon left in one can, I added that as well. Now the system has about 20 - 22 oz in it, and still has the same

With the engine running, idling, and fully up to temperature, the pressure on the low side reads 30.5 PSI. The high side reads 170psi. These seem low. If I'm reading the Factory Repair and Service manual correctly, the pressures should be 27 - 37 PSI on the Low side and 225 - 325 PSI on the high side. So it seems a little low, right?

Not sure what to do here. From everything I've read it seems the most likely thing I did was add too much oil. I'm not sure what to do from here. Try adding more Freon? How much damage can overcharging the system cause? If I take it to a shop to evacuate and recharge the system will that remove the oil I put in? Kind of a moot point though as shops want $200 - $260 for the service and I don't have that cash right now.

Any input or suggestions would be GREATLY appreciated!

Oh, and I forgot to mention that with the engine off and cool, the pressure in the system is equalized on both sides, and is about the same as the ambient temperature.
Thanks!

 

[KJowner]

Is it any better when you are driving at speed? Just wondering if the electric fan is running or if the evaporator is blocked.

 

[murdoc]

Thanks for the reply. No, it's the same at speed. Electric fan is running, and evap is brand new. Just replaced it and the heater core at the same time.

 

[LibertyTC]

My KJ's air conditioning is definitely not the coldest on the block. The KK may be very similar IDK.
I can only quote KJ specifications.
The lower idle at 700 rpm certainly does not meet specs. At a stop, I use neutral & rev it above 1000 rpm to get some cooling happening!
From the center vents this is the coldest I see

 

[murdoc]

Thanks for the reply. I'm getting the feeling that the this may be the case. That Jeep Liberty's AC systems just aren't great. Even with the shop manual it says that at best a normal temp is 45 degrees from the vent. It seems like most cars can dip into the 30's. I drop my wife's Mazda around the block to compare on the same day and when the best I got was 53, her CX-5 was getting 39 - 41!!! Since I didn't get this Liberty until it already had over 120k on the clock, I don't know what it felt like new to see if it is working "normally" or not.

My KJ's air conditioning is definitely not the coldest on the block. The KK may be very similar IDK.
I can only quote KJ specifications.
The lower idle at 700 rpm certainly does not meet specs. At a stop, I use neutral & rev it above 1000 rpm to get some cooling happening!
From the center vents this is the coldest I see

 

[john e denson]

I have 2005 lib and it works but it could be better. I read an article on this forum about putting a bypass valve on your hose going into the cab to the heater. Then open it up in the winter only. They say it helps. I live in FL and am thinking bout trying it.

 

[murdoc]

I have 2005 lib and it works but it could be better. I read an article on this forum about putting a bypass valve on your hose going into the cab to the heater. Then open it up in the winter only. They say it helps. I live in FL and am thinking bout trying it.

That's an interesting idea.

 

[LibertyTC]

Jeep should have programmed the engine to run at 1000 rpm when A/C positions are engaged.
I wonder if there is a way in programming to make that happen?

 

[john e denson]

Maybe just get a smaller sprocket for ac

 

[KJowner]

Just a thought, mine is poor in any position except recirculation, perhaps you have a stuck actuator or flap in the air box.

 

[murdoc]

Thanks, I just had the airbox out when I replaced the evap and heater cores a couple of weeks ago. Nothing was stuck at that time. However I did find that there kind of a rubber gasket on the edge of the blend doors that had complete melted down into a sticky goo on one of the blend doors, but not on the other. I cleaned the goo as best as possible.

Also, I'm measuring the temperature of the low pressure line right where it comes out of the evap core with a digital thermometer. And it is just a few degrees colder than the air coming out of the center vent. So, when the vent air is around 60 degrees, the low side pipe is around 52-55 degrees.