A/C problem

H SPALDING

MEMBER
2005 JEEP LIBERTY
3.7L
6 CYL
4WD
AUTOMATIC
93,000 MILES

First start vehicle A/C fine as engine warms up A/C less cold. Checked pressure low side jumps to 140 should be 45. High side drops to 100, Should be 175 What could the problem be?

Friday, August 25th, 2017 AT 10:24 AM

5 Replies

STEVE W.

MECHANIC
12,972 POSTS

That is a sign of a bad compressor. The compressor is trying to work but it is leaking internally so you get increased pressure out the low side.
If the compressor has not ruined itself to the point it has pushed debris into the system just changing it out should fix the issue. If it has pushed debris into the system you will be changing a few parts and flushing everything to get the stuff out.

Keep us informed.

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Friday, August 25th, 2017 AT 11:02 PM

H SPALDING

MEMBER
3 POSTS

I thought it was bad compressor. Today changed compressor, accumulator and line with orifice. First time using vacuum pump and manifold gauges. Pulled vacuum, it held, sticker calls for 22 oz. I believe I may have over charged based on the chart you provided. When I was done low pressure was 40-45 high pressure was 170 air temperature around 78-83. Cabin temperature cool but not as cold as it should be. Compressor is now cycling as it should. Confirm low pressure is to high for the temperature. Thanks for you help!

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Saturday, August 26th, 2017 AT 8:04 PM

STEVE W.

MECHANIC
12,972 POSTS

Low of 40-45 should be close for 80 degrees. Make sure the radiator fan is on when you check the interior temperatures.

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Sunday, August 27th, 2017 AT 10:21 AM

H SPALDING

MEMBER
3 POSTS

Radiator fan stays on, this morning used a cooking thermometer in center vent, inside temp was 53 out side was 55-60 today temp around 80 a/c on high not at all comfortable in jeep, set to recirculate this helped but just makes it bearable. I am out of ideas really need you'r help. THANKS

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Sunday, August 27th, 2017 AT 5:08 PM

STEVE W.

MECHANIC
12,972 POSTS

Yuck. Well it sounds like the electrical side is all OK. You just have an issue on the mechanical side. First thing I would check would be the temperature blend door. If it's open even a little the heater can overpower the AC. If you switch from AC to heat does it change OK?

Next you may want to try using some AC flush and cleaning out the other line and the evaporator and condenser cores. It's possible the compressor dumped some crud into them as it failed, a flush will usually clean it out. Then pull a vacuum and let it run for a bit to be sure all the flush and moisture is out of the system.

Now add some oil with dye in it for future use. Be sure to purge the line as you charge the system. You don't need to add air back in by accident. Charge it based on temperature and pressures.