Clunk sound when switching between recirculation and outside air modes in RX450h

[Geoff88]

Hi All, I have a 4-month old LX450h, which has three buttons: recirculation, auto, and outside air in a row together on the climate panel. I always selected the auto. In the last week, I often heard a soft yet noticeable clunk sound when the green light switching between outside air and recirculation buttons; this was also the case when I press the recirculation button directly. I can't recall that I have heard this clunk sound during the 4-month period. Can anyone advise if this sound is normal or some issues emerging?

Many thanks.

[Don C]

Hi Geoff.  Your signature says you have an RX,  your text says you’ve got an LX and you posted in the NX group.  Never mind, the point is that your RX rotates the air mix door through 360 degrees and there is an air admittance flap which can emit the clunk once per cycle.   Mention it when you go for service but I personally wouldn’t be concerned. There’s nothing in there to create a big problem.  

[Geoff88]

Hi Don, thanks for the advice. It was a typo in my text - it should be RX as you pointed. I am a new member, so thanks for pointing out that I posted in the wrong group.

[Geoff88]

Hello, I am a new member and I have a 4-month old RX450h, which has three buttons: recirculation, auto, and outside air in a row together on the climate panel. I always selected the auto. In the last week, I often heard a soft yet noticeable clunk sound when the green light switching between outside air and recirculation buttons; this was also the case when I press the recirculation button directly. I can't recall that I have heard this clunk sound during the 4-month period. Can anyone advise if this sound is normal or some issues emerging? Many thanks.

[steve2006]

Hi Geoff and welcome to the LOC.

Have you replaced the AC cabin filter since ownership began ?

I’ve also merged your 2 posts and moved them both to to the RX forum to avoid confusion.

[Geoff88]

@steve2006 Hi Steve, many thanks for merging the two posts. No, I have not replaced AC filter since I bought my RX in July. I noticed the soft clunk sound more often when another Auto button (next to the fan button) was also selected and when approaching traffic lights breaking to a stop. If I only use the auto button between recirculation/outside air buttons, then less often. 

[ColinBarber]

Worth asking your dealership for you to test another RX, either their showroom vehicle or a demonstrator to see if your one is abnormal. I'd expect to be able to hear the diverter closing position if you listen carefully when stationary but not when there is road noise. Possibly the gasket that seals the diverter is missing/dislodged.

[Geoff88]

@ColinBarber many thanks for your advice.

Just an update - I have visited the dealership this Wednesday. They have tested an RX450h demonstrator and also an RX450h with a 18-reg plate: both did not emit the clunk sound when switching between outside air and recirculation buttons when driving, and also did not emit noticeable clunk sound when directly pressing outside air and recirculation buttons when stationary. So this proves that the clunk noise I have with these buttons is abnormal. Currently, I am waiting to hear from them about if Lexus warranty would accept this under warranty repair. Fingers crossed.