I've been noticing a subtle sound like liquid is sloshing around when I get in and out of my 2023 IS 500. Car has about 15,000 miles on it. I've read that this could be a clogged AC drain or a clogged door drain. That seems unlikely due to the mileage of the car, but I'm not ruling it out. Has anyone else experienced something like that?

 

Standing outside the car, swing the door back and forth, hear anything? Then you’ll know if it’s the door or not.

 

Doesn't appear to be the door... swinging any of the doors does not make the sound.

 

Can you make the sound by rocking the car? (Use an open door to give you leverage.)

 

Yes, was just doing this. It seems to be towards the rear of the car, underneath it.
I did a little test drive, and I can see water slowly draining out of the AC drain. Very slowly.

 

How much gas in the tank? (Think you might hear sloshing on a less than full tank.)

 

This much.

Almost full. I filled it up yesterday.

Oh that would be so silly if it was fuel. It does seem like that's roughly where the sound comes from though.

 

yes, silly,,, but sometimes, we just notice things and go.. hmmm.. what's that? your normal.. no worries

 

I mean, I've been getting in and out of this car for over a year and a half, so you'd think I'd have noticed by now...

 

Too many slurpees ? I don't think you have a spare tire but is there a recessed area in the trunk?

 

What? I've got one of the coolest spare tires ever. 😂



No sign of water in here... maybe it's the fuel after all?

 

I actually remember hearing this noise.. I thought it was the gas in the gas tank. I was able to reproduce it when the car was in park and moving the car back and forth, no leaking though

 

You can open the sunroof and pour water in the drains to see if they’re clogged. Run the ac for a while and make sure you see it draining out under the car. You could also potentially have some air pockets in the cooling system

 

I assume your 500 has the same hidden pockets on either side of the trunk, under floor panels, like on my 350? One side houses the audio amplifier, the other side empty. Water intrusion ends up ruining amps sitting in that pocket. Can’t imagine that enough water could be in there to be heard as sloshing, but worth a check for piece of mind.

 

Have someone else rock the car while you stick your head under the rear end, to see if you can locate the sound.