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I realize I'm replying to a thread from 5 yrs ago but I wanted to ask if this problem was causing overheating? I just noticed the "hampster wheel" noise last week and then I overheated yesterday. I turned my climate control off and on and then turned on heat to HI and the engine temp went down enough to get home (5 min.) I'm just wondering if you all on this thread were more interested in heat and AC for cabin temp or engine temp? Thanks
Your issue sounds like a bad thermostat or low coolant, this thread is based in hvac heater temps
Yes, I checked an topped off coolant but neither of these would cause the hamster in the dash noise that has accompanied the overheat issue??
oh I thought you meant hamster wheel like as in maybe a water pump. That sounds like it may be a bad blend door motor maybe? I had to replace the two of mine on under the glove box, and the relay that's behind the heater core tube. The only actuator I did not change was the recirc one that's above the glove box area
OK, this is what I'm trying to narrow down. Would a bad blend door motor cause overheating? The noise sounds exactly like a vent or a damper opening or closing. Thanks
OK, this is what I'm trying to narrow down. Would a bad blend door motor cause overheating? The noise sounds exactly like a vent or a damper opening or closing. Thanks
OK, this is what I'm trying to narrow down. Would a bad blend door motor cause overheating? The noise sounds exactly like a vent or a damper opening or closing. Thanks
Running the heat at full blast can provide some small engine cooling benefit. I'd done this in the past to help bleed off some heat when I had an overheating engine while stuck in traffic in the summer. Not a pleasant experience.
But the engine overheat is not caused by the cabin heater.
Just wanted to post my results/thoughts. Maybe it will help someone else.
My wife's car (2001 RX300) was making this annoying BUZZING/GRINDING sound. And there was no hot air.
To get to the servo:
1) Took off the bottom panel below the glove box.
2) Took off the 2 hex screws at the bottom and 2 screws at the top of the glove box.
3) Unfortunately, my glove box was tethered to the airbag cord. So I had to squeeze the tabs to release the small panel, pull it through, then rotate the panel to separate from the glove box. DO NOT UNPLUG THE CORD!!!!
4) Remove 3 screws on the white plastic "vent" on the left side.
5) Remove the panel below that (has a flat-head plastic screw/snap on it).
Trying to see if maybe the arm was just stuck:
Next, I detached the arm on the air mix servo from the other piece, and turned the air to HOT, then COLD, etc. The arm on the servo did NOT move. So, the other guy's suggestion wouldn't work for me. Although, his pics were GREAT!
So, I had to take the air mix servo out:
The bottom 2 screws weren't that bad. But that top screw behind the pipes was a PAIN IN THE BUTT!
I was able to get the screw partially out with a stubby screwdriver (#2 phillips). But then I had to use a small ratchet with a #1 phillips attached. Both were at an angle. And wow, what a pain. Maybe the 2001 model is a little harder than others? It wasn't easy.
Then I just detached the servo cable.
Here's a pic of the servo out with the ratchet that I used to get that screw the rest of the way out:
Then, I took the servo apart. Turns out I had the same issue where the motor was becoming separated from the worm gear.
You can see that here:
So, I just used a gear puller (I had bought one a couple of years ago to fix the actuator for the door lock), to pull the "key" down the shaft a little bit. I'd guess about 1/8th of an inch?
Here's what the gear puller looks like:
Once I pulled the "key" out, there's very little gap anymore. So, it's not going to come loose again.
Here's a pic of the fixed servo:
Notice the extra space between the motor and the key after if was fixed (sorry that the angles were different).
Anyway, I didn't try to clean any contacts, or add any grease or anything like that. Just fixed the gear/key gap.
Everything works now. Servo arm moves all the way up (HOT) and all the way down (COLD). And the NOISE IS GONE.
Thanks to everyone for the info!
Is there any easy way to pull the key(I assume the goldish metal notch) forward to push the gear against the wall with some normal tools?
Mine is also moved towards the motor and making noise when changing modes.
Is there any easy way to pull the key(I assume the goldish metal notch) forward to push the gear against the wall with some normal tools?
Mine is also moved towards the motor and making noise when changing modes.
I'll answer my own question.
I used a flathead screwdriver on each side and simultaneously pry upwards lightly against the motor body.
Put it all back together and no more grinding noise.
Very happy this was fixable and didn't need replacement.
My best of luck after I fixed the mode servo, I found out there was no longer heat coming out and it's winter time.
I opened everything up and this time got the air mix servo out.
It was not moving the arm at all as if it was either faulty or not getting the signal.
I've cleaned the contact fingers and the orange area on the wheel.
There are grease on the green area of the wheel, do I clean the grease in that area too?
Also, I tested the motor with a 9V battery. It seems to only turn one direction and refuse when I change polarity.
I checked the same pins on the plug and after starting car, it is supplying +12v and -12v depending on max cold or max hot input at the plug.
I think the motor refuses to turn the other way(to hot direction).
I can only get it to spin the opposite way if I rotate the shaft by hand a few times.
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:
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!
Anyone know the measurement for the hex screw?
I'd like to change it while putting things back as it was painful to take the originals screws out.
