With the front air conditioner running on a hot day I notice occasional cycling of warm air coming thru the AC vents. It does it in both recycle and outside air mode. Dealer says they can't detect it. Does anybody else have this issue? This is on a 2004 GX470 and I've noticed it since new. Please advise. Thanks.

 

Sounds like you have a leak somewhere. I had warmer air out of the drivers vents only, passenger's were cold. Dealer found an o-ring that was leaking. They replaced o-ring and refilled the system, all is good now. Keep on them, have a tech drive with you so he can see the problem.

 

what is your temp set on? do you run automatic or do you manually adjust your settings?

 

I always have it on automatic at desired temp setting. It is not consistant so the tech when driving might not experience it.

 

on a hot day, what temp do you set it on? what's a "hot day" temperature when this occurred?

 

Lexus does have a TSIB out for insufficient A/C cooling. Involves adding some parts to make the system more efficient. Might be worth a look since you are in Nevada.

 

+1.

Ask them to check to see if your vehicle applies to the TSIB. It is more than likely that from what you describe.

 

Temperature set at around 72 to 74 probably on a hot day. A hot day in Las Vegas can be 100 to 115+. It will cycle some warm air driving around town or on the Interstate. It's not fussy. Is there any more information on the TSIB mentioned or a site that I might visit? Thanks

 

hmm. well that's enough of a temp differential to keep it from shutting off the compressor momentarily! what if you set the temp to say...65?

 

I don't think it matters where it is set. The warm air comes thru on a hot day.

 

well, i'm just trying to isolate your problem. of course it matters where you set it, that's how the system knows what temperature to try to achieve.
the climate control system relies on several different temp. sensors in different locations to maintain the set temp inside your car. sometimes at a not very cold temp of say 74*, the ccs may think it has reached its goal of 74* and temporarily turn off the compressor.
so if you were to set it at 65, that would make sure that the system continues to blow cold as it will never get 65* with the ambient temp over 100*.

 

You're probably right but when it set at 72 and it's 115 outside I don't think it would ever cycle off. I can't try it now for a test because it is only 60+ outside. Can't Lexus run tests without driving in high heat and waiting for it to happen. Thanks again for your input.

 

i would think you're right about it not cycling off at 72 when i'ts 115, but these things aren't perfect.
your dealer can only check to make sure you have no leaks, your freon is full and that there are no codes in the ccs module. if all that passes, they really have nothing to go on until they can actually duplicate your concern.
i'm interetsted to see how this turns out, but i guess we have to wait until you get hot over there again, like when, June?!

 

Thanks for your help. I did manage to find a TSIB regarding a possible sensor problem but they weren't specific about any symptoms. I will ask the dealer to investigate and hope that they actually do. The O-ring leak that somebody above had sounded similar to my symptom. Do you have any idea if the problem is addressed and made a part of my record prior to the expiration of my original Lexus warranty, that they would still cover it after the 4 years which ends this March 8? I have purchased the Lexus 7 year/75K Extended Warranty but it's not as complete as the original bumper to bumper warranty. I'm just wondering what you think. I will report back with the results. Thanks again.

 

typically, if you have a complaint while you're still in original warranty, but no conclusion is arrived at, you can still continue the concern after the warranty is up and it will be covered, since it was not addressed to satisfaction the first time.