StratfordShark

I've noticed that when I slide the HVAC control to 'off', I sometimes hear a tremendous and frightening bang from area of passenger (i.e. on left, this is a RHD) footwell.

Always gives me a fright! Haven't done ay systematic tests to see when it happens but I think it's done it even when the engine has been off. At any rate I presume it must be some kind of vacuum operated valve that is operating explosively!

I don't have aircon at the moment (at some point before I owned it the headlamp motor arm had put a hole in the aircon radiator). Recently went through the HVAC and renewed one actuator (footwell) and sealed off the other leaking one (central comb).

Not likely to be anything crucial but grateful for any pointers on what's making such a racket, and some tips for fixing.

Thanks

SeanR

Recirculation flappy for the HVAC.

If you hear it, it works.

Nicole

There were times when people were happy when things just worked.

Then came Lexus...

StratfordShark

Thanks a lot for the answer.

Yes I can hear it fine! Presumably not meant to operate so noisily though?

It makes sense that it does work as I remember the blue vac line (recirculation vent) was fine when I checked it for holding vacuum.

ROG100

Its a large flap and the foam cushion has disintergrated and now when it closes its plastic to plastic hence the bang.

StratfordShark

Thanks for that Roger!

I think I'll put it at bottom of to-do list, but sounds like it would be nice to replace the flap someday and looking at John Pirtle's description it doesn't seem too tricky - have dismantled a few things in that area.