RX400h water leak

[SeanM16]

Maybe this has been covered before but last winter my 2007 RX400h developed a severe interior water leak, spreading from the inside driver footwell to the rear foot wells. Videos on YouTube can be found showing this issue. I also reported it to Lexus main dealer during a recent air con recharge but they were oblivious to the issue. No such problems this year yet but with winter soon to take hold I’m wondering if my carpets will once again be sodden. Anybody else experienced this and had it investigated/sorted? Cheers

[Spacewagon52]

"Oblivious to the issue" sounds about right. Check this forum, lots on sunroof drain blockages. Read the threads and you should be able to sort it out. Get your Lexus serviced at an independent. Unless the car is less than 10 years old - Lexus dealers will not want to know.

[Parrot of Doom]

Put wads of kitchen roll or toilet paper around the footwell, above where the water pools.  The paper will get wet as the water passes through it, but not wet from the pooled water below it.  That way, you'll be able to find out where it's coming from.  From thereon it's just a matter of tracing it up through the car.

[PCM]

On 10/17/2021 at 9:50 PM, SeanM16 said:

Maybe this has been covered before but last winter my 2007 RX400h developed a severe interior water leak, spreading from the inside driver footwell to the rear foot wells. Videos on YouTube can be found showing this issue. I also reported it to Lexus main dealer during a recent air con recharge but they were oblivious to the issue. No such problems this year yet but with winter soon to take hold I’m wondering if my carpets will once again be sodden. Anybody else experienced this and had it investigated/sorted? Cheers

Any update following the heavy rains last night?

[nigel@dernley.co.uk]

I'm also in Kent. Must be the rain. I drive around with newspaper under the mat and it's usually soaked. My RX400 also has a leak, driver side. The sunroof drains are ok, as are the door drains. I've put newspaper up below the dash and there's no evidence of water dripping down. I'm sure it's coming in behind the carpets. There was no problem in the summer, even after rain. It's almost as if there's a container that fills up because it can't drain and overflows and in the summer it has time to dry up.

I put clngfilm over the wipers, at the back of the bonnet, to block water going in and it did a little. If I pour water down the drains at the side of the wiper well it comes out under the car, as expected.

My local independent who is very good, can't find anything and are not keen on digging too many parts out.

 

[Malc]

and last nights huge blustery rain might have impregnated too maybe ?😭

Malc

[kenhall]

Apologies if this has been posted before.

This RX330 owner Eric Kirkhuff, “The Swiss Army Knife” has a YouTube video showing how he overcame the awful Lexus design for the front sunroof drains where they basically drain into the chassis and exit via a slit drain. Restricted drainage due to crud build-up in this difficult to access area can lead to water overflowing into the footwell.

The YouTube video is titled “Lexus 2004 RX330 Wet Carpets & Water Leaking “Hack-Fix” and Insight on other Models”.

He has made more videos addressing other RX water leakage problems which may be of interest.

 

[Herbie]

You mean this one Ken?

 

 

[kenhall]

That’s the one!

I must figure out to open the link in my post - any tips?

[kenhall]

If you don’t fancy drilling holes in your car then the alternative fix is to pull the sunroof drain tube out of the existing sill cavity drain and add more tubing to extend it under the footwell carpet/insulation and out through the large rubber floor grommet.

[Rx400hse-l08]

The drains maybe blocked either by debris or kink in pipe I researched when looking to buy my one there were a lot of how to videos depending on how good you are at tackling things your self I recall having to strop footwell corner then removing a unit behind it but my lexus dealer Edgeware road were able to locate that there was a problem with one side of the drain but wanted £1200 plus to rectify it as they said headlining had to be removed so decided to leave it for now and tackle after winter as no garage but currently car is under cover when not in use 

[Xavier]

Hope this helps any one but if you have a leak that appears to be coming from the roof, my best advice is to take the roof rack and the brackets off and take that weatherstripping seal off. 9 out 10 times the factory roof seam seal has dried and cracked. Alot of people seam to use flex seal but you can get the ac Delco one off amazon

[tgnana]

In a 2007 RX400h, I have had "Check Hybrid System" error, which lead to car not getting "Ready" to drive. It turns out there was a pool of water under HV Battery. Yet to find the source of water.

[Russell Wheeler]

Loads of places it can be coming in from. Rear seams, rear light clusters, just below the back bumper, roof rails. Basically these cars are like a sieve as they age. I have sorted most of mine out (they hide water well under the boot so you can't see it), then drilled a couple of holes in the boot, so if water does get in, it can get out without getting to the HV Battery.

[hughseh]

On 6/8/2024 at 3:54 PM, Russell Wheeler said:

Loads of places it can be coming in from. Rear seams, rear light clusters, just below the back bumper, roof rails. Basically these cars are like a sieve as they age. I have sorted most of mine out (they hide water well under the boot so you can't see it), then drilled a couple of holes in the boot, so if water does get in, it can get out without getting to the HV battery.

Can I ask how you rust proofed the holes you did? Both sides, what product and what locations? I'm tempted to go down this route as a fail safe, I assume noise ingress isn't a worry that far back and under the layers 

[Russell Wheeler]

On 6/11/2024 at 2:11 PM, hughseh said:

Can I ask how you rust proofed the holes you did? Both sides, what product and what locations? I'm tempted to go down this route as a fail safe, I assume noise ingress isn't a worry that far back and under the layers 

Just drilled the holes then squirted some zinc primer on, seems fine. No change in noise either -I didn't drill massive holes.Behind the back wheels