Air condition system in my car?

Question

I have a weird problem with my A/C unit in my car. I have a older car in which I believe their is a small leak in the a/c unit. Recently, I put coolant (or whatever that stuff is you place in the a/c) into the car.
For some strange reason the A/C blows cold air in the morning hours and late afternoon. It only blows hot air in the mid-afternoon hours (the time I need it the most).
It is to my understanding that the A/C Coils good be to hot for the unit to kick in. The part I am confused about is that if it is 90 degrees in the mid-afternoon and it is 90 degrees in the late afternoon, then why does it only work in the late afternoon?

Any suggestions?

Answer 1

I'm going to suspect you added R-12 refrigerant, not coolant. probably your A/C thermostat isn't working, or your A/C pump clutch needs servicing. Trace the two aluminum pipes from your compressor/pump then turn on the car and start the A/C wait two-three minutes, safely feel them, one should be cold near the radiator)and one should be hot(near the passenger side). If there's no difference, you have a problem with the pump or clutch.
If there's a difference, then it's the A/C thermostat located in the passenger compartment.

Answer 2

Here's my take on this. First, if you know there is a leak in your AC then there are actually two possiblities here.. either you have too much Freon (coolant) because you just filled it up and over filled or you have too little freon because you haven't put freon in a while and it some has leaked out. Either condition will not allow the A/C to function at it's most effecient. You stated that the outside temp is 90 so I'm am going to assume this is the norm for your area which is HOT and therefore your A/C needs to work at it's most effecient to keep you car cool.

I suspect your A/C is working the same both in the morning, mid-afternoon and late afternoon. This is due to the fact that nothing changes on the car between these two times. Therefore we should look to outside influences and in this case it would be the cause of the heat, ie the sun. In the morning and the late afternoon the sun (source of heat) is lower in the sky and farther from your car and therefore exerts less constant heat on your car. In the mid-afternoon, the sun is overhead therefore the heat is at it's most intenst and it is constantly being 'refreshed' by the proximity of the sun. You stated that the temps are the same mid and late afternoon. This is true but in late afternoon the heat is not being 'replentished' by sun as it is in the middle of the day. Therefore in the late afternoon as the A/C begins to try to cool down the car it has to simply cool in interior air. While in the mid afternoon the A/C is trying to cool the interior air while the Sun is causing more heat on the outside of your car and thus radiating this heat inside and therefore 'competing' with the A/C over the temperature of the air in the car.

So.. how to fix. Well.. unfortunately... you'll need to get the A/C leak fixed to resolve this delima. This leak could be expensive and it could be cheap depending upon where the leak is. However compared to the cost of freon this may be cheaper in the long run and you'll be cooler and happier.

Hope this helps and good luck!

Answer 3

you are still low on freon ( the gas that goes in the ac unit) sounds to me like it only works when the temperature is lower. if the system is low then whens it cooler it will work better, when its warmer it causes the system to cycle ( shut off and on ) which would cause your not working so well. also you didnt meantion the yr of the vehicle and what kind of gas you put in, there is a difference between R12 and R134a and you Cannot mix them with good results

Answer 4

TAKE IT TO GARAGE THAT HAS THE AIR CONDIT CHECK EQUIPT...HAVE IT REFILLED....IF IT HAS A SLOW LEAK IT WILL STILL WORK FOR THE SEASON OR POSSIBLY TWO...THEN GET IT DONE AGAIN...ITS WORTH THE COMFORT AND DEPENDABILITY.....OTHERWISE BIG REPAIR BILL..

Answer 5

be may the system gets to hot