Inconsistent temperature from air vents

[knishida]

I have a 1991 LS400, which except for the faulty LCD clock/climate control display, has never had a problem before with the climate control.

Recently the air conditioner has been unable to cool the car. I just had the refrigerant checked and filled and this is not the problem. I do notice that 3 out of the four front panel vents blow out air at whatever the outside temperature happens to be. the 4th vent blows out cold air. I also noticed that there were thin pieces of foam, probably a gasket, that I believe came out of the vents (pulled a small piece out of one of the vents the other day) around the same time that cooling problem occurred. I think that maybe outside air is leaking into the vents through these torn gaskets.

My mechanic says that I need to replace the evaporator and compressor, which would run around $2,000. Does anyone have any similar experience with this problem? I'll probably get rid of the car, if I can't find a lower cost fix.

Thanks,

Ken

[AWJ]

It is a 91. I might guess that the gasket could be part of a seal in the duct work that had come out and as a result the cold air does not make it through all of the ducting. Just a guess. You would need the diagram of the ducting and seals and the ability to get at the area in question. That is pricey for that kind of work. If you like the car find a cheaper place to fix it. Otherwise, move on if you must. How much do you want for it?

[zeta]

this has happened to some of the ES members over at CL. when the A/C is turned on, heat comes out. but it's also not always, it's like sporadic. i'm not sure what they did to fix it, but it's fixable without too much cost i'm pretty sure.

edit - see if you can take it to a lexus or toyota dealer and ask them to check the a/c expansion valves or the freon in your car. those were the problems with the ES's but i'm not sure about the LS. a checkup shouldn't cost too much. just ask them to check the entire car for a problem, or take it to a small shop for cheaper.

[bpricetex]

I have the same problem with my 1996 ES300. I am 200 miles from a Lexus dealer and have been to 5 repair shops. We checked the pump, freon, lines, evaporative cooler, expansion valve, and looked for obstructions. Talked to another mechanic about the computer. No luck yet; cool passengers & hot drivers.

bpricetex

[jbarhorst2]

Have any of you had the electric doors checked?? These doors control the flow of cool or hot air to the various vents. You could have a bad motor or you could have a blown fuse or something. It may be worth looking into because it could be a simple fix. Sorry I don't know more to tell you where to start looking.

[tt9714]

I'm having a similar problem with my 95 SC400. The compressor is engaging, but I only get hot air out of the vents. I just had my R134a recharged, so I know that is OK. I believe that it is the "air outlet servomotor" since I received diagnostic code 43.

Do you guys know how to check the A/C controller diagnostic codes? With the key in the OFF position, simultaneously hold down the "AUTO" and "RECIRC" buttons while turning the ignition key to ON, then release the buttons. The A/C display should flash 4 times, then a 2 digit diagnostic code will flash. If you get "21" that is for the solar sensor, and it will always come up unless you are in direct sunlight. Low refrigerant pressure is code 23.

[Bondrake]

The thread starter had the same problem as I am now having. My thought was the electric doors too, but a wiring diagram and locations would be nice...

[Bondrake]

Did anyone find solutions to their problems? I am still having an issue. Regrigerant is fine, pulled open the evaporator area and there is icey air coming from there.... it's just not making it to the vents for the most part.