Car a/c intermittent failure

[leebee]

The a/c in our car doesn't work all the time. Today it was fine from here to store A, then on to store B, but didn't work on the way home. It also didn't work when we went out to lunch. It's beastly hot- real-feel this afternoon was 105F- and it's impossible to drive much with this heat and no a/c. We had it into the shop about a month ago and they checked for leaks and recharged it. Anyone have any guesses of what might be wrong?

 

[Dan Murphy]

Anyone have any guesses of what might be wrong?

Here are several possible causes, leebee, all sound like a possibility. The heat here is similar, opressinve.

https://www.google.com/search?q=Car...yAEAmAIAoAIAmAMAkgcAoAcA&sclient=gws-wiz-serp

 

[tvguy]

Take it back, should be under warranty.

 

[Rex1993]

We had it into the shop about a month ago and they checked for leaks and recharged it.

If you have a car built in this century and someone recharges your A/C, you have an issue in the system. It is a closed system and the only reason you would need recharging is that there is a leak somewhere. Sometimes this can be old seals or loose connections but it's never just needing a recharge and all is good.

 

[tvguy]

If you have a car built in this century and someone recharges your A/C, you have an issue in the system. It is a closed system and the only reason you would need recharging is that there is a leak somewhere. Sometimes this can be old seals or loose connections but it's never just needing a recharge and all is good.

A leak test should be the first thing done. However, SAE considers a leak of 1/4 ounce per fitting to be normal, so you can just lose refrigerant and need topping off.
https://autotechac.com/ac-facts-and-myths/

A/C Fact: The Society of Automotive Engineers (SAE) designed the A/C fittings that are on your vehicle. These fittings have a SAE acceptable leakage rate of 1/4 ounce of refrigerant per year per fitting. That does not sound like a lot, but the average vehicle has 8 fittings. This means that you are losing 2 ounces of refrigerant per year. It is recommended that you service your air conditioning every 2 years. This will ensure that your compressor is never “starving” for oil. The older vehicles used to have systems that held upwards of 36 ounces of refrigerant. Today’s vehicles have much smaller systems that require as little as 15 ounces of refrigerant. The need to service your air conditioning has become much more important with these reduced capacities or system damage will occur.

 

[Micca]

leebee I'm concerned you have an a/c curse that is following you around--first at work, now in your car. You may need to organize a sacrifice to Nigel--god of the British Thermal Units

 

[sam_gordon]

Take it back, should be under warranty.

What warranty? If there is a leak (which is my guess), that wasn't fixed, so it wouldn't be covered.

 

[Stratman50th]

It might be the plenum door is getting stuck in the closed position. Depending on the system it can be caused by a vacuum leak or electrical problem at the switch or door.
Can you hear the compressor kick on?
Or, coolant gas (don't know what flavor is in your system) leaking out as said above.
The test will be does it work again the next time you go to use it.

 

[Moliphino]

Is it blowing warm air or not blowing at all?

 

[tvguy]

What warranty? If there is a leak (which is my guess), that wasn't fixed, so it wouldn't be covered.

OP says she paid for a leak test a month ago. I would think any reputable repair shop would warranty their work for at least 90 days if they missed a leak.

 

[sam_gordon]

OP says she paid for a leak test a month ago. I would think any reputable repair shop would warranty their work for at least 90 days if they missed a leak.

From what I remember when I've gotten my cars worked on, there's a "superficial" leak test, that I think just involves looking for leaks, then a "more detailed" leak test which includes putting a dye in the system to help find the leak. Of course, the more detailed one is more expensive, and isn't done until after the first one and it appears there is still a leak.

 

[LuvOrlando]

We did this once and it was fine

https://www.autozone.com/diy/climate-control/how-to-recharge-car-ac

I tend to go to the auto places by myself, the people behind the counter are often mechanics and willing to help me 9/10 times

 

[TiggerTrigger]

Is the vehicle still under manufacturer’s warranty? You will have more leverage if it is. I went through something like this with a VW Atlas a few years ago, they couldn’t fix it and bought it back from me. I might also do some searches to see if this is a known issue with the model/year. It could lead to seeing their solutions. Forums (vehicle ones) and facebook groups would be good places to start.

 

[Dive Bar Casanova]

If its intermittent it's usually from an incorrect refrigerant charge.
A great DIY fix is charge it yourself. Check out how to do it YouTubes and decide.

Sometimes after a shop checks the charge the Schrader service valve will slightly stick open and refrigerant gas will seep out. Found that to be the problem recently with the wife's Mazda, then a few years back with our Truck.

 

[tvguy]

From what I remember when I've gotten my cars worked on, there's a "superficial" leak test, that I think just involves looking for leaks, then a "more detailed" leak test which includes putting a dye in the system to help find the leak. Of course, the more detailed one is more expensive, and isn't done until after the first one and it appears there is still a leak.

Could be. I'm in California and it's illegal to recharge an auto a/c system here without a dye test first. Cost depends on the shop labor rate. My mechanic charges $100 an hour and he charges an hour labor for a leak test.

 

[sam_gordon]

Could be. I'm in California and it's illegal to recharge an auto a/c system here without a dye test first. Cost depends on the shop labor rate. My mechanic charges $100 an hour and he charges an hour labor for a leak test.

Once again, not everything operates the same across the country as it does in CA.

Take it back to the shop saying "it's not fixed"? Sure.
Assuming a future repair is covered under warranty? Not so much.

 

[jalapeno_pretzel]

I had intermittent heating one winter, and it turned out to the be the head gasket. Not sure if intermittent AC would be indicative of a similar issue.

 

[bcla]

Could be the compressor clutch. If you don't feel it mechanically "kicking in" (even with a poor refrigerant level) then the compressor isn't engaging. That's something that's extremely noticeable.

 

[Mouse Tracker]

#1- Do you have confidence in the shop ?
#2- Evaporator/condenser issue? Cleaned?
#3- To check the refrigerant level the system has to be fully evacuated then filled (dye test)
#4- Compressor working properly?
#5- Interior compartment issue like a blend door not working (if blowing or not)

 

[princesscinderella]

I had an intermittent issue with just one zone of my ac on my mini van where it would blast the heat at me instead of the ac while all the others worked. I brought it in multiple times for the issue and it end up being a sensor that was defective, since it was a zone controlled temperature system.