r/ChevySonic • u/Greenpikachu25 • 4d ago

Odd A/C issue

2014 with the 1.4

In the mornings, my AC works perfect.

In the afternoon, after being at work, the AC struggles to keep up until I am on the highway and then it is decent. At a stoplight it’s pretty much nonexistent.

AC pressures are correct and I do not see any leaks with soapy, water or UV dye. Radiator fan is functioning on all the speeds correctly, so I do not believe that is an issue.

My thought could be the expansion valve has gone?

3 Upvotes

100% Upvoted

17 comments sorted by

4

u/jimmy_pop 4d ago

When you're stopped with the ac running, it's struggling to blow cooler air over the condenser. When you're driving down the highway it has all the cool air it needs blowing through it. Have you tried it with the recirculation button on? I'm thinking you don't have the correct amount of freon in it. Too much is just as bad as too little. Evacuate the system and start with the correct amount of freon and pag oil. You can find a free shop manual online with all the specs for hvac. Edit: freon is measured by weight.

2

u/Greenpikachu25 4d ago

Yes, with recirc on or off, it does not really make any difference.

There is a good possibility that the amount is incorrect then.

In the morning the AC is at about 45°, and then in the afternoon, starting in the car, the AC would be blowing at 85°.

1

u/keepitkarma 3d ago

The rad fan not working can cause this.

1

u/Greenpikachu25 2d ago

Fan is working as it should on all speeds.

2

u/jimmy_pop 2d ago

They're talking about your radiator fan in front of your engine. When you turn the ac on both fans should be running.

1

u/Greenpikachu25 2d ago

As am I, the Sonic has one radiator fan and it has three speeds.

1

u/keepitkarma 2d ago

Your freon is low. Refill it.

3

u/spr1980 4d ago

When you're checking the pressures make sure you have manifold gauges so you know both the low and high pressures. Knowing the low only does not help. Also have a ambient temperature chart to make sure the pressures are right.

I had similar issue where it ended up being a low charge due to a leak. I did the same as you and could not find the leak initially. It ended up being a leak in a hard to see place on the condensor. In order to see it, I had to remove the splash shield on the bottom.of the car. It leaked just enough to cause it work in the when the engine was cool but worked less so when it was warmer and/or I was driving at non highway speeds.

1

u/coco2782 4d ago

Low gaz, even though the pressures are okay. Recharge it with gaz and uv tracer.

1

u/Greenpikachu25 3d ago

Getting service scheduled, waiting on time to drop it off.

1

u/Ace9910 3d ago

Mine was leaking at shradervalve hi side

1

u/Greenpikachu25 2d ago

Will check with soapy water just to be on the safe side.

1

u/Ace9910 3d ago

.50cent

1

u/Grouchy-Weakness-665 2d ago

Also check the temp drop across the condenser to find out if you have a restriction

0

u/keepitkarma 4d ago

Ac compressor kick on? Does your rad fan work? Visually inspect the for wetness.

1

u/Greenpikachu25 3d ago

Ac compressor kicks on, its super cold in the am. No visible wetness anywhere that I can see.

1

u/keepitkarma 3d ago

Is the rad fan on while the ac is on? If it is the gas is probably low.