RX400h - wet carpet

[Buritonian]

Hi - there is plenty online for this issue for RX3** and GS*** but not specifically the RX400h - mine is a 2006.

I've got a soaked carpet in the drivers side (UK) footwell - I pulled up the carpet, removed the drain plug and squeezed out the fluid from the carpet underlay, so I can then observe where the water comes in from. 

Sunroof drains tested fine

Drain around the wipers also tested fine

windscreen seal tested fine 

(by tested, I mean that i ran water through/over successfully without ingress)

so now I'm thinking I must have a leak some place underside (though it looks healthy) or that the AC drain (or another drain) is blocked... the latter is where I could use some help. 

I see other threads (on other models) speak of the AC condensation drain or a grommet needing to be cleared... but I can't see where such a tube pops out underside.

Also where is it topside... could I pop off the top end to clear it just as easily?

How long should aircon run on full cold before it produces some draining fluid (so I can test this)? 

Worth noting that since lifting the carpet, I have driven it 20mins (with the carpet out) with aircon on full but did not see any water dropping under the car or into the footwell when I stopped. I can't be sure if this water came in whilst driving in rain/puddles or whether the water arrived into the footwell regardless of weather. hence I'm keen to do more aircon tests whilst the weather is good and roads dry.

Any help will be gratefully received as my only other options seem to be to give it to a lexus mechanic or accuse my wife of having spilt water and not confessed (though I saw well over a litre of water come out the carpets when I rung them out so only jest about this).

First step - test the air con/clean tube and see how that does. There after it will be drives in the rain/puddles and see what happens... Insert other media

  

[jonathanca14]

A Fellow 2006 RX400H owner with water problems!! Have you checked if the boot floor is wet (under the plastic storage compartments)?

From what I understand the source of a lot of wet carpet problems seems to be the boot , it leaks in through all sorts of places (rear lights, bumper brackets ect) trickles in, becomes a puddle and then eventually roles down into the HV Battery area and on to the floor wells.

Plenty of posts on here with advice on where to start hunting for the leaks, I've followed a few my self! Let us know where yours ends up being 🙂 

[Buritonian]

Hi - Thank you for replying - I spoke with the independent Lexus workshop I use for servicing and with their help I've ruled out the AC drain pipe as that's apparently on the passenger side for the RX400h and my problem is exclusively driver side (UK). They steered me towards the weld seams at the top of the rear quarter where it meets the boot and roof (between the boot hinge and boot gas strut fixing). They said it was a common spot on the 2006. I used a seam sealant on it and have been drying the carpets by rotating towels in/out from under them every day. Only had one rain shower in this time but dare i say, I don't see new water ingress. Monitoring the situation now with fingers crossed.

I haven't lifted the plastics boot compartments to check under those yet - it looks a bit of a job to get them out. is it?

 

[rich1068]

Getting everything out of the boot is a doddle once you know the correct procedure. About half way down this thread I link to a YT video.

If you've had water coming in it's well worth checking this area.