Why does the A/C in my van only get cold when I get going?

[Misty]

This was a gradual process.. didn't happen all at once.. but my A/C does not get cold unless I am accelerating.. the faster I go, the colder it gets. It seems to be getting worse and worse over time. So, on the highway, we are nice and cool.. But when we are sitting idle, like in a parking lot or at a stoplight, we are suffocating!

 

What is causing this and what can I do to fix it?

 

Thanks!

[Dad 4 Boys]

You most likely have a very tiny leak in the refrigerant circuit somewhere. Your refrigerant is slowly leaking out, which causes the system to work more inefficiently.

 

It gets better when you accelerate because the refrigeration compressor is spinning faster when the engine is turning faster. That allows the compressor to do more work on the reduced amount of refrigerant.

 

You have a couple of options if you do indeed have a leak.

 

The first is to take it somewhere to be diagnosed. They should check the amount of refrigerant in the system. If it's low, they will add refrigerant to get it back to the correct amount. If a leak is suspected, this added refrigerant will include some type of tracer. This tracer will aid them in tracking down the leak.

 

The second is to add refrigerant yourself. You can buy do-it-yourself cans of refrigerant at auto parts stores like AutoZone, Advance, NAPA, etc. or even possibly in the automotive section at Wal-Mart. These do-it-yourself cans include directions, the proper connection hose and a gauge that will tell you when you have the right amount of refrigerant in the system. Obviously, this doesn't fix the leak, but it could get your A/C back to where it used to be. You could also Google how to add refrigerant to your car. I'm sure there's plenty of online information on this subject.

 

Depending upon how old your vehicle is, you will either have refrigerant R-12 (Freon) or R-134a. R-12 is in older cars, and you won't be able to buy it. Everything in the auto parts stores will be R-134a. I don't know exactly when the change from R-12 to R-134a occurred. I have a 1995 Camry that uses R-134a. So if you're vehicle is newer than that it's most likely R-134a. You should be able to find that information in the owner's manual somewhere.

[Lisa in Jax]

When my van did this, it was due to a leak in the radiator. The car was near overheating anytime I idled and it automatically turned off the a/c to protect itself. So, idling = HOT car inside, and driving = cool car.

 

Get your radiator checked. Once my radiator was replaced, the a/c was ice cold all the time. :)

 

Lisa

[Misty]

You most likely have a very tiny leak in the refrigerant circuit somewhere. Your refrigerant is slowly leaking out, which causes the system to work more inefficiently.

 

Thank you! This is so helpful!! Another symptom we have is when the A/C is turned on, there is a fast "clicking" noise under the hood... Something is spinning and you can hear it (sort of like the wheel on the Wheel of Fortune, only more high pitched). When I turn the A/C off, the noise stops. I guess that's the refridgeration compressor that you mentioned?

 

Sure wish hubby were here and not deployed on a submarine right now!!

 

Thanks again for your helpful information.

[Misty]

When my van did this, it was due to a leak in the radiator. The car was near overheating anytime I idled and it automatically turned off the a/c to protect itself. So, idling = HOT car inside, and driving = cool car.

 

Get your radiator checked. Once my radiator was replaced, the a/c was ice cold all the time. :)

 

Lisa

 

Thanks, I will keep this in mind as a possibility.. I have not had any overheating though.. :confused:

[Ravin]

could it be the fan? How well does it blow with the AC off? Do you usually have it set to recirculate (in which case that probably isn't it) or to bring in outside air (which gets stronger when moving and stops when car is at a standstill).

 

Our blower died gradually, kicking in and out at random, working better when the car was moving, and then died. So now the only A/C we get is when the car is moving and passive air through the vents blows it into the car. You can really only feel it in the driver's seat, but it helps a little.

[mrs.m]

Mine is doing this too. I suspected a leak. I guess I better take it in. I just want a new van though.

[abreakfromlife]

mine is similar and we know it's a radiator leak :tongue_smilie: We just keep refilling the coolant until we have the $$ to get it fixed :glare:

[MomsintheGarden]

Great post, Dad 4 Boys!

 

My dh (RegGuheert on these boards) bought a 1994 car for our ds. The AC must have had a slow leak, so they bought a couple of cans of R-134a at WalMart, and 10 minutes later ds's car was nice and cool. You can check the pressure to make sure (it's temperature dependent, remember PV=nRT from Chemistry?). Dh and ds check the pressure every once in a while to make sure it's ok. Total cost = about $12 (yay!). Inspired, dh recharged our other vehicles. It worked well.

 

1994 was the first year cars were required to use the new coolant (R-134a), so you can be sure that any car made then or after uses it. Before that, it was optional, so you'll need to check.

 

Hope you get cool soon!

GardenMom

[Misty]

Thanks everyone! My van is a 2004 model.. Easy enough.. so I will pick up some coolant today and then ask my step-father to help me out with it!