After searching I didn't see any posts about this, so I thought I'd ask. My 95 sc300's a/c is noticible colder when the car is moving. When driving it is very cold even in the 100+ degree texas heat. When the car is sitting still however, it is probably at least 10 degrees warmer. Is this normal with for this car with the high temps? Maybe the condenser is dirty...the car does have 137k miles.

Thanks guys and gals,

Brian

 

Congrats, it is working correctly.

 

when you are moving, the car wind passing through your a/c condensor is disappating the heat. When your stopped or moving slow, not enough wind is moving through the condensor to move the heat out.

 

My father's LS400 isn't affected nearly as much though, thats why I was asking. I'm in and out of different cars all day long and there seem to be plenty of vehicles out there that still have very cold a/c when you sit still. I sold my 96 mystic cobra two days ago, even it had ice cold a/c when sitting. I'm new to the SC, I've only had it for a month...so maybe I'm just not used to it yet.

 

oh, I forgot to mention that if you're driving on the highway, and the a/c is nice and cold, if you have to stop moving for more than a few minutes it gets much warmer very quickly.

 

Mine does the exact same thing, I know it's normal because i recently replaced a lot of the a/c system due to leaks. so it's all new parts. 2 of the reasons the SC does that is because it uses a mechanical fan for both the a/c and radiator, most cars have a seperate electric fan to move air through the condensor when the car is sitting still, also when driving the engine rpm's are above idle and thus the compressor is turning faster and pushing more refrigerant through the evaporator inside the dash.

 

Ahh, that makes sense. I didn't think about only having the crank driven fan, as all the cars I'm comparing this to have electric fans. Duh! Thanks for all the help!

 

mine does the same thing and every a/c component including the compressor was replaced a few thousand miles ago...

 

Me thinks you guys got it all wrong....

This is my understanding - The higher the engines rpm's rev (engine moving faster) the faster the belt driven A/C condenser (motor) turns which makes the freon move faster which creates colder air that fans into the car cabin area...The little electric fan that blows the fan air whether it be hot or cold remains the same regardless unless you change the climate control settings manually...The A/C Has nothing to do with the outside wind or speed but everything with engine speed.....Try putting the car in nuetral and rev the engine with the A/C on and you will notice the air gets colder fast.....

Remember fellas - This is not a radiator it is the airconditioning system that is sealed off from the outside elements.. Hope this info helps...

Your cars A/C is acting normal, but you could be getting low on freon...Get it charged freshly and it will always blow colder at idle...

 

mines always cold never gets warmer at a stop

 

Today i pulled my car in at the shop and did some maintance work. I had been noticing a musty odor from the vents with the a/c on. We have a product at the dealership we use alot which is a foam based a/c system cleaner. you basically inject the foam directly up the drainage tube into the evaporator case, it fills the case and as it dissolves, it washes away all of the mold, dust and garbage that get stuck to the evaporator fins. then it all just drains right out the tube just like the water does.

after doing this service, on the drive home i felt a noticable difference in the vent temp with the a/c set to 66 auto. even at a dead stop it blew icey cold. it also doesn't smell bad anymore.

Maybe the issue with some of these cars, especially the ones without cabin air filters installed is a dirty moldy evaporator core.

just a thought.

 

usually with electric fan setups, one fan on a dual fan will kick on when the ac is running.

you need airflow through your condensor or whatever it is called to get your ac running cold.

 

Jrmoskal, how much did that foamy stuff cost you to do? I just had a major rainstorm up here and my AC smell made me wanna puke :|

 

Like any system, it is a system. If you ac works at freeway speeds your compressor and condenser are working. If you are low on freon you will have your symptoms as you are describing a system at the edge. The Lex sys is designed with a lot of spare capacity. You seem to lack air flow over the condenser at low/idle speeds.

1. There is a fast idle feature that kicks up the idle speed the instant you switch on the ac. My SC 400 and any modern car I have looked at had this feature. It is there mostly to keep the engine from stalling but does enhance the ac perf slightly. Might only be "contributing" to your problem.

2. Low on freon, as I said. That problem will give your sympt if it is "just" low enough.

3. If your evaporator were plugged with dirt and the system were up to spec in all other regards you would have bad performance across the board. Foam squirts wouldn't change much. Engine or road speed wouldn't help.What you are smelling is "wet moldy dirt".

4. The mechanical fan IS the most powerful fan you can use. The stock item is great until you start doubling the HP and even at that your engine overheats, not your AC. The Aux electric fan on some cars helps at low speeds. I don't have an Aux elect fan but if you do it should come on when you switch the AC on. If you have one and it is malfunctioned....it would cause your symptoms.

5. Fan shroud. If you have a car that came stock with one and yours is missing.....thats probably your problem.

6. You know that plastic sheeting that Lex hung under the front of the car beneath the radiator, air dam and front of the engine? The items that are attached with a zillion screws and clips. The one that prevents your engine fan from re ingesting the hot air it has just sucked through the radiator? That would cause your problem.

7. FAN CLUTCH last but not least. The most probable and cheapest fix is replacing this item. Try this: Warm you engine up real toasty. Open the hood and have someone rev you engine real quick and hard. Your fan should ROAR. I have verified that the fan clutch is bad by simply spinning the fan on a hot engine right after it is shut down. Also, a bad fan will "coast" to a stop when the engine is turned off. These guys have a life span and are considered "consumables".

See Gazi if you need shrouds. Even if they aren't your current problem you should have these items in place. Another function they serve is that they keep dirt out of your engine compartment. Dirt in a Lex....quick...do something!

 

The product is made by Auto Solutions, I work at a toyota dealership and we sell it retail at 12.95 for the kit, this is easy to do yourself at home, just use a catch pan under the car to catch the liquid that drains out after the foam is injected, i've seen some really nasty mold and stuff come out of there.