Servo Under Dash

carld · September 18, 2015

Does anybody know of a remedy or temp fix, ive over the last 2 weeks started to notice a noise under the dash and ive been told it is probably the servo that controls the heater directions.

steve2006 · September 18, 2015

There are several servo motors under the dash which control airflow through the various vents and perform cold/hot air mixing.

When the car ignition is 1st turned on it is normal to hear the servo flaps moving to their preset positions.

Have you checked to confirm the air comes out of the correctly selected vents ( windscreen demist, face level,footwell) and the temperature range is available.

Removing the pollen filter on certain Lexus models without the climate control set into a certain mode can cause damage to the flaps.

PCM · September 19, 2015

Q. Is it more prevalent when the air con is on?

( I had that, and it was a servo motor )

carld · September 20, 2015

Thanks for your replys unfortunately it is on constant, even if i only have the ignition on when my wife pops into a shop it is very annoying. I have checked all the different cycles and there is no position where fhe air is restricted.

PCM · September 21, 2015

I guess the fix is to identify and change the motor.

( The colder weather may(?) help? )

I was lucky, I had mine done under warranty - but it would have driven me mad eventually.

ChrisKaye · September 21, 2015

Is it like a constant whirr or clicking?

Some US owners have stripped the servo's down and reset & relubricated the noisy mechanism which has worked for them, although it is fiddly and time consuming. Is it something you feel you want to tackle yourself?

The only alternative may be to get a non-noisy second hand part which maybe more of a plug n play swap than taking the whole unit apart to fix. There are a few posts with pictures on the US CL site I can help you track down if you fancy some DIY!