A/c only cold at highway speeds - Toyota Nation Forum : Toyota Car and Truck Forums

cjagg25 · 07-02-2007, 03:26 PM

88Camry ..The car never actually gets real cold, but it will never get cold unless you are at highway speeds. As soon as you slow don or come to a stop it starts getting warmer.
Also it takes forever for the air to get cool. I could run the a/c in park position for 15 minutes and come back out and it isn't even that cool, but the faster I go the colder the air gets.
I hooked the hose up to it to put the refrigerant cooling in it, but the recharge hose said it was full. I was told that you can't just hook it up you have to actually back it out to relieve the pressure in the lines or you woulodn't get an accurate reading.Is this true!

whats the best thing to do to make the a/c get cold & quickly?

atobe · 07-02-2007, 03:53 PM

may be the AC fan's not running ?

SilverSportNOLA · 07-02-2007, 10:29 PM

Firstly .... if you do not know what you are doing you will make the problem much worse.

Your car is an 88 .... R134a was not in the A/C systems of 1988 Automobiles from the factory, they use R12. Unless you have a license, or an old supply, you have not been able to buy R12 for at least 10 years now. Older systems can usually be converted to run the currently availble R134a .... was that ever done on you car?

As for the letting pressure out, that is to get air out of the lines to the guages, if you put air into the system you will have problems.

Check that the fan is coming on as stated above. Get the system checked, and if you do not know if it has R12 or R134a in it, do not try adding coolant, get it to someone that knows how to get it working correctly.

ozzi · 07-03-2007, 08:29 AM

Sitting at idle with the A/C going is hard on a lot of stuff under the hood of an old car. I would avoid it if possible, particularly when the outside temp is around 100 or so.

I do not even mess with A/C systems anymore since I cannot buy the R-12 myself. This is one of those jobs I now farm out. If you bought freon it might have been R134 and it may not be compatible with your system. I have heard stories both ways. A converted system is not mechanically compatible with the R12-type connectors.

I'd convert to R-134 only if I had to replace lots of stuff. I have heard there is a new refrigerant for consumers to buy that is compatible with R-12, but I have not checked it out.

I don't follow your description of the adding freon. Open the freon valve and let it escape at the manifold as you tighten the fitting to the manifold. Open the can valve and the low pressure valve. The can will have enough pressure to push the freon into the low pressure side of your system.

Check the high and low pressures. If they indicate low freon, top off the freon. Recheck the pressures to determine if your system needs more repair.

Check the idle RPM control, outside air intrusion, and consider window tint. The temp inside depends on the heat coming in minus the heat extracted by the A/C.

As cars age seals dry and leak around windows, doors, and within the freon system. My 87 functions properly, but probably because of age, it does not cool well around town. On the freeway it freezes me out.

In the past I've had a broken interior heater/ac vent door broken that was allowing humid air in and causing my evap to freeze up. That was hard to find.

Check the idle RPM. It needs to get a little bump higher when the A/C is on. Mine is set too low so occassionally I'll press the accelerator to help it out at a stop light. Crack the books to see what your car would have in idle control.

marc780 · 07-04-2007, 11:21 PM

First try cleaning the evaporator. Its probably full of dirt and bugs and this will reduce the cooling ability. (evaporator is located on front of the radiator). Use low pressure water and compressed air and blow the dirt out of the fins and see if there is any improvement.

But since your cooling is affected so much i think the others may be right and you just need to try a recharge. I dont think you have a serious leak just a minor one, since you can still blow some cold air. You may want to consider changing over to R-134 with a kit, R-12 is very difficult to find as not only can you not buy it without a refrigerant handlers license, it is no longer being manufactured.
http://searchwarp.com/swa15436.htm

You can get a kit with fittings, gauges and instructions from walmart for like $20 or 30, if it isnt the right one for your car it may be some more but les than a shop would charge for sure. You do not want to overcharge with the refrigerant, this will make it worse - the method they tell you in these kits is you hook up the gauge to one fitting and add the freon til it reads in a certain pressure range. Then you ought to be blowing cold air just like new.

wiccanferret · 07-05-2007, 11:36 AM

Quote:

Originally Posted by cjagg25

88Camry ..The car never actually gets real cold, but it will never get cold unless you are at highway speeds. As soon as you slow don or come to a stop it starts getting warmer.
Also it takes forever for the air to get cool. I could run the a/c in park position for 15 minutes and come back out and it isn't even that cool, but the faster I go the colder the air gets.
I hooked the hose up to it to put the refrigerant cooling in it, but the recharge hose said it was full. I was told that you can't just hook it up you have to actually back it out to relieve the pressure in the lines or you woulodn't get an accurate reading.Is this true!

whats the best thing to do to make the a/c get cold & quickly?

When I bought my '90 Camry I was told the same thing by the previous owner. My initial diagnosis which was based on my '89 Celica was the VSV valve which is responsible for idling the engine up when the AC is on...and I was right!

When you look at the AC compressor when it's off, you'll see that the inside of the pulley does not move. Turn it on and you'll hear a -click- and the car should idle up a bit. Look again at the AC compressor and the whole pulley should be moving. If not, or if the car is idling like poo, then you'll want to grab a VSV Idle Up valve. It's black with a shiny mount/backing, it sits on your firewall via one screw and it is attached back toward the intake manifold via two tiny vacuum hoses. It also has an electronic connector. Grab one for an '89 Celica GT if the dealer quotes you some $200 for yours. They're the same part as tested by me.

SilverSportNOLA · 07-05-2007, 01:46 PM

Or you could just bypass it like someone did mine .... there is a pic here a few weeks ago I posted on a thread I started of how it was done. The car will be idled up all the time, even when the A/C is off ... but it isn't more than 100 - 150 rpm.