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Sloshing sound?

Well, we let my son take our 2009 Subaru Forester across the country to college, and of course, the car seems to be having issues now. He says he is hearing a “sloshing” sound under the car towards the rear (cargo area) whenever he stops or goes over speed bumps. He insists that he has looked under seats and in crevices for loose items with liquid in them, and nothing. He also hasn’t noticed (yet) any spots on the ground under the car. Anyone have any idea what this could be before I send him to some mechanic in LA I don’t know? (I’ll be looking for one in the mechanics files.)

Perhaps it has collected water in the trunk where the spare tire is located.

Well, interestingly enough, my son looked into the spare tire well and noticed a small amount of brown sticky liquid and a seam that isn’t all the way closed. He’s sent me some pictures… I still think there’s more fluid/liquid that’s actually causing the sloshing.

That open seam is just sloppy work or was the car rear ended at one point?
I’m pretty sure those two pieces are supposed to be welded together and then it is supposed to have a bead of seam sealer over the area to seal it all. With the seam sealer missing, I’m leaning towards sloppy work. You could get Subaru to fix it, I guess, but I doubt they’ll do it for free.
While it wouldn’t make it a ‘nice’ fix, you could tell your son to get a caulk gun and some good quality seam sealer (www.eastwood.com sells it along with most car body supply stores) and go to town. I’d seal the bottom first so you can see the crack and then seal the top. It applies much like any other caulk.
You don’t want the weather to get in and rot that area out.

That’s clearly not the area where the sloshing comes from, though.

Perhaps ask to have someone sit in the back seat to see if they can pin point the noise. A gas tank obviously has liquid in it but it has baffles in it to keep it from violently moving around. On some tanks they are plastic and get unseated.

If one of the baffles got loose, it may not hurt anything under normal driving conditions, other than that the noise is annoying.
On some cars, on a tank that’s nearing empty, it could cause the car to hesitate when you’re cornering or going down hill.

Maybe he is letting the gas tank get to almost empty is all that is happening here. At home, the gas tank is kept above 1/4, but at college – well, you know …

I notice on my car – a Corolla – some slight sloshing sounds when the gas tank is almost empty.

Other than that? Well, with a college student I’d say look for a forgotten half filled beer keg somewhere under a huge pile of laundry? lol

Best of luck

Thanks RemCo and GeorgeSanJose,
Great advice from both of you-- I will communicate this info with my son. No doubt about an almost empty gas tank is possible. I’ll have him get the seam sealer (and no, this car has never been rear ended as far as I know…).
I have to say, with all the love Click and Clack give Subarus, I’m not sure I would buy one again-- this one has had a string of issues from the time we bought it. Maybe we got a lemon?
As for a missing beer keg, well he was incredulous that I would even suggest that…
Thanks again

I think he has become paranoid since the incident in which the under body damage occurred (the spare tire well is bent causing that seam to split).
He is likely listening to the fuel in the tank which may be normal but the tank should be inspected for damage if that spare tire well damage is from a recent mishap.