Hello first time poster long time lurker.
I bought this 2018 GX 460 last April.

I’ve noticed a funky smell from time to time and attributed it to dog and stinky gym clothes, cargo ETC.

We’ve had some wet PNW weather and the smell has gotten much worse. The carpet under the rear passenger seat is wet and is the source of the smell.

So far:
-Tested/ reamed front two sunroof drains (they flow water just fine)
-Removed trim, peeled back carpet to find source of leak.


The AC drain hose appears to be the source of the leak. It was sitting in the firewall hole loosely and I could stick my finger through. While the hose itself is free and clear of obstructions, it appears my leak is outside rain water splashing in from the firewall. Hard to picture, but there are water stains coming from below the hose.

I ordered what appears to be the correct grommet 888993A010. As mine appears broken (see pictures).


Plan forward:

- disarm airbags/ remove passenger seat tonight.
- peel back carpet
-hand dry/ clean backside of carpet and floor
-run space heater/ dehumidifier in interior for a few hours
-spray foam and carpet with enzyme cleaner.
-clean evaporator with Toyota HVAC cleaning kit.

Questions:
-Is the fitment of the AC hose in the grommet supposed to be loose?
- can someone confirm my grommet is broken/ incorrect based on pictures?
-Is there anywhere else I should check for leaks?

Any other advice is greatly appreciated




I removed AC hose to show there isn’t really a seal in here. It just fits loosely in the hole. Trail of water stains under felt, hard to photo.

Mildew on floor pans

This was the grommet for the AC drain tube, does it look broken?

 

Looks like the grommet is damaged, so just replace it. AC hose should not be excessively loose.
Was the windshield ever replaced? I have seen poor installation jobs cause water leaks.

 

The windshield is Lexus branded so I’d assume it’s original. May be a good idea to run some water over it while the interior is out and check for leaks though. I’ll do that.

 

Make sure the drain tube isn't blocked. Spiders like to make nests in them. Lexus makes an anti insect tip to prevent it.

 

Thanks for the tip, I ended up pulling the drain tube and sink tested, verified that it flows water.

In case anyone ever digs up this thread or has this same issue, I'll document my experience with this repair:

On Saturday, I removed the passenger and drivers seat/ trim. Pretty easy, except the rear seat airbag connector was a bit of a puzzle.

In order to get the carpet lifted, you have to remove the audio amp and brackets under the passenger seat as well.
The trim clips holding it in need the center pushed in to release.

From there, I was able to flip the affected carpet toward the drivers side so it stood up vertically.

I put a dehumidifier in the car overnight. I had to figure out how to force it on rather than function on the humidistat. Once I did that, the padding under the carpet dried very quickly.

I then sprayed and soaked all the affected padding in a product called Concrobium Mold Control. The instructions say to let it dry, as the dehydrating action kills and "crushes" mildew. This is also free of chlorides, and creates an Alkaline environment, which is not corrosive to the mild steel floor pans.

The slightly bleachy smell of the cleaning product overtook the strong mildew smell in the car when it was wet. I ran the dehumidifier overnight and to my surprise, there was no sign of any odor left!

Before I put the interior back together, I'm going to nose the GX out of the garage and hose down the windshield and sunroof just to make sure water isn't getting in from anywhere else.

 

Picture speaks for itself left new grommet right old

 

Water coming in the trunk area eventuall runs forward into the passenger foot wells. Straight shot from elevated trunk deck. Misled us a long while on the source of the leak. Check rear seams and drains. there are two drains that connect into hoses, one on each side just in front of the vent flap box (black plastic box either side).

ALso leaks come from the body seams in the rear. Ours leaked both sides from there.

Open up the back and see if it’s wet underneath.

White in this pic is liquid sealant and reinforced seams with, leaks came from hoses and body seams above.

 

Just to conclude this thread, the source of the water was the grommet. We drove the GX through a couple rainstorms on a road trip this weekend and everything stayed dry.
To anyone else facing this issue, I definitely recommend a household dehumidifier to dry things out.
The only thing I would have done differently in the future is run an Ozone generator when the carpets were pulled up and dry, but I couldn't get my hands on one quick enough.