A/C works only when it's Cool outside (weird)

[guinnessman]

It's funny, today driving to work it was around 88 degrees, and my AC set to MAX and 60 degrees blew warm air the whole 35 minute commute to work.

I get off work, it's low 60's outside, and the AC was on i forgot to shut it and it was blowing ICE COLD as soon as i fired her up.

I've noticed this for the past 2 years i've had my 96 LSC, when it's warm or hot out, there is no cold AC, but it's ice cold when it's not hot out lol.

WTH am i missing here? PS i filled up the ac system last summer and the same crap lol.

 

[zmt325]

is your compressor kicking on?

 

[1bad4.6l]

Wash out your condensor and get the bugs out of it.

 

[MediumD]

The extra heat might make the pressure just high enough to shut off..

 

[ProjectRedMark]

If you have proper line pressure on both the high and low sides but poor cooling at higher temps your system probably needs to be evacuated and recharged. Moisture builds up inside A/C lines over time and reduces the systems efficiency just like if you have air in your brake lines. Properly evacuating the system will remove all of the moisture and draw it down to a vacuum. Then good clean (moisture free) freon can be recharged into the system. Another possibility is the orifice tube (filter in the A/C line) may be partially clogged. If that is the case you will need to have the system evacuated and replace the orifice tube. If I remember correctly the orifice tube is not replacable separately from the A/C line on our cars. You would have to replace the whole line or get one of the kits that let's you cut out the section that has the orifice tube and splice in a new section of line with a new orifice tube. Those kits work great but keep in mind as with any splice it gives 2 more potential leak points. The correct repair would be to replace the whole line if needed.

To recap if your pressures are good the most likely cause is moisture followed by the orifice tube. A professional shop should be able to help you determine which is the case.

Sorry for the long reply but I hope it helps.

 

[JDS353]

make sure your blend door is working.

 

[Sapperfire]

Just like air in your brake lines ??? I'm not even going to touch that one

 

[ProjectRedMark]

Just like air in your brake lines ??? I'm not even going to touch that one

Yeah I know. Yet another bad reference! I meant if there is moisture in the A/C lines it will cause poor cooling especially in higher temperatures. Like air in a brake line will cause poor braking power. Not the same principle I know that. Just trying to make a point

 

[rayner601]

sounds like a low refrigerant charge. When the a/c is on during the day, how often does the clutch kick on/off?

 

[LaserSVT]

I concur. Need to evac and recharge the system. You can rent the pump from Vatozone and if you get the nice synthetic extra cold kit with the hoses then they will hook up to the pump to evac the system (pump does not include hoses).
Can do the whole thing for under $45 which is a bit cheaper then a shop job and I know from experience and have proved it in my friends shop that the synthetic stuff that says cools 10% better actually does when properly used. I did it in my 97 and it was down right fridgid in that car no matter what the outside temp was. I need to do it to my 98 as its A/C is cold but no where near the 97's.

 

[ProjectRedMark]

I concur. Need to evac and recharge the system. You can rent the pump from Vatozone and if you get the nice synthetic extra cold kit with the hoses then they will hook up to the pump to evac the system (pump does not include hoses).
Can do the whole thing for under $45 which is a bit cheaper then a shop job and I know from experience and have proved it in my friends shop that the synthetic stuff that says cools 10% better actually does when properly used. I did it in my 97 and it was down right fridgid in that car no matter what the outside temp was. I need to do it to my 98 as its A/C is cold but no where near the 97's.

+1 on the synthetic freon. I didn't know autozone did evacuation or rented the pumps. That's good to know.