RX330 Climate Control Problem

[white3ch0c0late]

I'm having a bit of a problem with my mom's RX330. A few months ago, we were coming back from a trip from up north in the RX, and we got caught in traffic. All of a sudden, the CC went out. It was just blowing warm air, no matter what temp we set the CC to. The traffic was so bad that we were actually sitting in one place for 15 minutes, so I shut the car off. Later, when we started moving again, I drove for a while without the CC, and then after about 10 minutes, I tried it again, and it worked... for 5 minutes, and then went dead again. No cold air. Only warm air. I left it on for a while, and finally the cold air came back and its been working ever since. BUT.. since that day, from time to time after extended use of the CC, there's a really faint humming sound that I believe is coming from the climate control system. I'm not sure what it is. The CC hasn't gone out on me since that day, but its done the humming noise from time to time. My mom took it in to Lexus for a service and told them about it, and all they did was change the A/C filter... fuckers. She's taking it in for another service on Monday, and I'm going with her this time so that I can talk to the techs.

I believe that it might need a Freon treatment, but I don't know. I've never seen this kind of problem, and its the first car I've driven that has climate control instead of just a regular A/C. So I've never dealt with it. Anyone have any ideas?

[digger08]

Sounds like maybe just low on 134A (not freon) - continuing to run the system will cause further damage - so do an inspection soon.

Simple check for a small cost - find a place that will do a pressure test on the AC system - Try a quick lube or an AC repair specialist - Cost is usually less than $100.00 - dealer inspection will cost alot more than this! Full replacement will be in the thousands, so get it tested first.

They will create a vacuum inside of the AC system by connecting an AC machine to the high and low lines - These are quick connect lines, so no tear down is necessary.

If this test passes, they will also weight the amount of 134A refridgerent in your system ( somewhere around 2 lbs or less) - If it is low, they will replace the refridgerent and oil - Usually about few oz of oil inside as well..

If not this then, you can proceed to check the other areas, condensor etc...

Mine went through very similar symptons you describe, It turned out my system was operating with about .6 of a lb of refridgerent. So topping up was all that was required. There was no leaking, just R134A escaping over time through seal membranes.

Good luck

Thats about all I know

Digger08

[white3ch0c0late]

Thanks, man! I appreciate it. Yeah, if anything needs to be replaced, the car is still under warranty, and its completely stock, so the warranty isn't void. Thanks for the response.