momo2000

Interesting.  OK, I was going down path of problems with the servos that control the flow under the dash.  Mine was doing that, hot on one side and cold on the other, but never completelty went to hot on both.  Mine was actually the servos and I could here them making noises for years and then they failed.   Sounds like you actually have a leak.

Are you saying that when it blows cold air on one side (passenger) at the same time it is blowing hot air on the other side (driver) or vica versa?   Trying to understand if if the WHOLE SYSTEM is either hot or cold.    OR if it is a SIDE thing where the two SIDES are different.

Just went through this with my 2003 GX470.  Yes it is very BOUNCY/ROUGH for a few mins.   I'd say you have a leak in one of the pneumatic cushion/air bags, whatever you want to call them.  Mine I could typically hear the Right Rear one leaking when I parked it.   You need to get this taken care of, because the air pump is very expensive, so you don't want to burn it out . . . if your leak is really bad, and it is working a lot when you are driving . . . then you'll have one more thing to replace.

The bags from Lexus seem to be about $300 each, and then labor to install, so seems to be $800-$1,000 to get done at Lexus.

There are lots of folks on the forums that DIY the project.  You can find plenty of instructions.

I was interested in doing it myself, so I ordered the parts suggested from eBay for $158 for the pair www.ebay.com/itm/Rear-Air-Spring-Bag-PAIR-for-2003-2009-LEXUS-GX470-TOYOTA-4RUNNER/231771928392 but jacked up one side to do a “preliminary check” and the tops of the bags are “way up there”, and I just didn’t see any way I was going to get to the “clip” to release them. So, I opted to have my non-dealer Lexus mechanic do it. He charged me $181 (plus tax). So, for about $350 I am back in business.

Good luck, and let us know what happens.

I have a 2003 with 215K miles on it.  Had it since 90K, great truck! 

 

Part I: 3-4 years ago the (what I call) air flow control boxes (one under each side driver/pass, control which vents the air flows out of) started making noise.  They still worked, but would pretty much make time almost all the time the car was running.  Just a clunking, chirping, clicking every few seconds, somewhat rhythmic.   Again, everything worked, just made noise.  Since I am the only driver, and am alone 95% of the time in the truck, and play the radio ;), I never worried about it, just called them “my pet squirrels”.  I spoke to my “non-dealer-lexus-only” mechanic that I’ve been taking it to since I got it and said the dash would have to come off to fix it, and it was a big price tag so I have lived with it.

Part II:  Then 18-ish months ago I got the recall notice about the cracked dash and went in to get on “the list” at the dealership (Dec 2015).  The cracked dash did bother me much, but I though, great, when they take the dash off for the repair, I’ll pay the dealer whatever their fee is to change the air flow control boxes that that time.  What a great and fortunate plan!

Part III:  I am still waiting to get “my turn” to get the dash fixed, but about a month ago, the air flow control boxes stopped making noise, but now I think they are stuck in one position.  Here is the condition that they are now it.  I get A/C out the vents on the passenger side, but on the driver’s side, it blows HEAT.  I close the vents, but I some still comes through, and I some is coming through the floor vent.  After another 85+ degree day in Atlanta, I am motivated to find a solution.

QUESTIONS:  has anyone ever seen this issue?  Is there any way to manually operate these “air flow control boxes” so I can put it in the “A/C flow mode” for the summer??  Any other ideas to keep me a bit cooler?

[GONE]    I've got an '03 GX470 with tan interior.   I've had the 3rd row "Jump seats" stored/wrapped in my garage for years, but am moving.  Since I never use them, I'm going to get rid of them, I was hoping someone might want them, instead of me just throwing them in the trash.   I live in Alpharetta, GA, and they would need to be picked up in the next few days.  You can have them for free, but I wouldn't turn down $20 for a pizza  ;)

Sent you an pm.

Step: are you able to send me a PM as well? I have a '03 GX470. Thanks.

Hey, thanks! I purchased a used '03 about a year ago, and that was the only thing wrong. I've wanted to replace it, but haven't taken the time to investigate. I "stumbled" on your post, and will go do it now that you have done all the "investigation". Just wanted to say thanks!!!