Gruss

Thanks for all the help here; I had no trouble with the 'troublesome" screw on my '03 - I just used a stubby #2 philips. I also did not have to remove the mode servo to remove the air mix servo; pictures below in case they help anyone.

Interestingly, after I took it apart and found no play in the worm gear, I put it back together and now it's just working again, so I put it right back.

Even if it's only a temporary "fix" I'm not worried because I know how "easy" it is - I am confident I could add a replacement in a half hour or so.

vietrx300

My wife's 2001 rx300 has the same problem. I tried to backflush the heater core but it did not work. It costed me $210.0 for nothing. I wonder what kind of backflusing the dealer had used- just tap water or with heavy duty chemical to remove scales.

Viet

ilscott

The problem screw can be removed in a few seconds using a flat bladed jeweler's screwdriver and a pair of pliers.

mizak82

I did this a couple days ago in less than 30 minutes... I had a regular, medium and mini screw driver and i was able to get all 3 screws out of the servo without much difficulty.. what i did too is swap the screws from the white air flow foot vent and used them when i put the servo back in in case i ever have to remove it again the threads wont be dull or stripped (which is a possibility bc of the angles)..

takaiguchi

Did you ever fix this? Mine is doing the same thing and I cannot get it fixed. Cool air on drivers side but warm to passenger.

vietrx300

Yes. I finally replaced the heater core, brand new, $70.0 (including shipping from US to Canada). After replacing, I got full heat both side for a week then the symptom came back. I double checked the inlet pipe, it was connected to the TOP, switched to the BOTTOM, refilled the coolant, NO heat at all (reason: air pockets). Kept driving for a week( I live in Canada sometimes the temp dipped down to -30C, too cold to fix car without heated garage) Now I have heat back.
If you want to replace the heater core by yourself. Here is the trick!

It is impossible to pull the heater core out without removing the whole unit. I found this task is very difficult and time consuming. In addition, I have to disconnect the AC line, too. So I decided to do the easy way since it's my car.

I used small air die grinder to cut off the two pipes about 3-5 inches, pulled it out. Matching it with the new heater core and cut the same positions. Used heater hose from the old lexus since this hose is a little bigger than the pipe so I could slide it back and forth easily. Installed the new heater core back in, connected the pipes using hose clamps

Good luck!

sylvia

could I please get help with where is best to order the air mix servo motor, \I have the same issue, \RX 300 always problems with heat/A/C when changing seasons, it is defect of Lexus RX300 I think, Sylvia
I would appreciate part # and web site where is best to order .

sylvia

actually the problem is that the screw holding the motor gets easly broken, the pictures are very accurate, \I had the same issiue, the last 2 years \I was able to remove the shoulder to switch off from cold to hot but not anymore, it just broke

sylvia

Please could \i get the part number, i need to order that asap and the letter and numbers on it lead me nowhere, i removed it already arm broken

salimshah

You have plenty of choices.
http://lexus.sewellparts.com/ is what I use and you can register at that site with your CL membership user name and get CL discount.

Browse through the parts catalog to get any part number. Make sure you give them your vin number as part number for your vehicle can be different.

rock auto is another site.

Salim

ShogunSTL

Had the same problem, and luckily, thanks to all of you guys, I saw that the car I bought last week (not from a Lexus dealer) had no coolant. I put new antifreeze in there, and boom, warm air!

Thanks homies!

yakev724

I am tackling the servo issue and would like some input.

It seems as though the contact arms have ground down the circuit paths on the wheel.

Will these still work if greased or am I looking at buying new parts?


Thanks

salimshah

The answer is obvious!

Salim

yakev724

It was, before I saw this post:

https://www.clublexus.com/forums/6087630-post53.html


Anyway, will be ordering replacements...

JimBowNut

Thanks for the photos! This thread is the only one that directly addresses my problem of no heat (air-mix) on my daughter's 2001 RX300.

The problem is related to high humidity. Gotta have a little heated defrost to handle this situation this time of year in the southeast, (Especially in the rain).

My fix is not complete yet. The problem I found was that the pin on arm of air-mix servo had popped out of arm on blend door. I still have to decide whether to replace this servo or not. There is some wear on the arm of blend door. I just cannot justify a whole new air-box assy. The servo is working however, this is not first time this has happened. I'm sure the disengaged servo arm is exactly what happened before, when ex-wifey took it to firestone. So........

[1] I can buy new servo and replace it, but it still may disengage.

[2] I can clean up old servo and reinstall it, but it still may disengage.

[3] I can take old cleaned up servo and engineer a solid bolt-on, or riveted connection, to blend door arm
that is slide washered so it will not bind as servo does its job.

I'll have to do some thinking about the design of the connection to arms, servo, etc. I'll get back to you guys when I've got it.

jim

EDIT

RESULTS.....Well, I put on a new servo after taking apart the old one. It was worn down similar to some of the other servo pics already on the thread. I decided to wait a bit to see if the new servo disengages from the blend door arm before engineering a fix that may not be needed.

I decided to change the screws to a hex screw. See below pics:

http://i1268.photobucket.com/albums/...g?t=1406674909

http://i1268.photobucket.com/albums/...g?t=1406674921

http://i1268.photobucket.com/albums/...g?t=1406674931

http://i1268.photobucket.com/albums/...g?t=1406674940

http://i1268.photobucket.com/albums/...g?t=1406674906



That little 1/4" ratchet was the bomb! I just cut the bit down to just barely holding in the hex socket. Also, that little 1/4" ignition wrench worked perfectly in that tight spot!