Gas Tank Sloshing?

PsyDoc

Member
Hi.

My wife just purchased a CX-9 Touring this past Saturday. Early Sunday morning, I took it out to see how it drives. Air conditioning and radio were off, so there was no noise in this "ultra-quiet" cabin. When I hit the brakes (not a panic stop, just firm), I could hear a sloshing sound coming from the back. I rolled forward about 5 feet and hit the brakes again...slosh, slosh. I assumed it was the fuel sloshing around and was somewhat concerned as this should not be happening on such new vehicles. Doing some internet searching, I found that, in some gas tanks, baffles only go up about 1/2 way or so. All the test driving my wife did, the car had about 1/4-1/2 tank and the radio and A/C were on; of course, they filled it up once she bought it. I went to the dealer today and my wife's salesman and I checked out another CX-9. No sloshing, but the tank had less than 1/4 of a tank. The salesman is going to fill it up and try it and then is going to call me back. Anyone else noticed this? I would not have noticed it otherwise, but it was early morning, no traffic noise, and all the accessories were off. With the radio on (not very loud), and A/C on, you cannot hear it.
 
Update

The service manager called Mazda and Mazda said that some sloshing can be heard when the vehicle has a full-tank, due to the baffling design of the gas tank. Once the gas level goes down a bit, the sound will go away. I only noticed the sloshing with a quicker than normal stop, as stated in my initial post, and only with a stop. A dip in the road, going up or down a driveway, etc. did not cause any sound. I am just too damn anal-retentive and have the curse of noticing EVERY little thing. :)
 
Update #2

Wife got home and I did what I did on Sunday...no sloshing, weird. My wife thinks I'm crazy (nothing new there) and I'm hearing things. The gas indicator is not even 1-tick down from the "Full" indication on the fuel gauge. Perhaps the dealership "overfilled" the tank on Saturday evening. Oh well.
 
Never noticed it, but I will drive quiet and see if there is any sound since I'm on a full tank.
 
new cars defies physics and their gas tanks stops gas from sloshing and moving about :rolleyes:

get real!
 
Same thing happened to me while backing up from my driveway. Usually goes away after getting below 3/4th of a tank.
 
Yes, I noticed the sloshing as well when pull into garage (turn down the music volume). This usually happens when the gas tank is 90-95% full. This happens to many vehicles I have owned. This, of course, if a design issue, but I wonder if there is anything Mazda can do at this point. I certainly hope so.
 
haha I have the same problem but I dont even care about my cx-9 anymore, my tank is sloshing, my driver side mirror is vibrating, when I steer , a weird noise comes from steering box, my cx-9 can only go 260 miles with a full tank, the black plastic fenders turned into light gray, the output in trunk doesnt work anymore, my dealer doesnt have a service schedule, I got 15k miles on my car and they only change oil but nothin else.
 
My wife heard it yesterday with a half tank of gas. Whoopee do.. It will not harm anything and I have heard this in much more expensive vehicles as well.

Enjoy your ride and think to yourself louder and it will be ok (nana)
 
haha I have the same problem but I dont even care about my cx-9 anymore, my tank is sloshing, my driver side mirror is vibrating, when I steer , a weird noise comes from steering box, my cx-9 can only go 260 miles with a full tank, the black plastic fenders turned into light gray, the output in trunk doesnt work anymore, my dealer doesnt have a service schedule, I got 15k miles on my car and they only change oil but nothin else.

Sarcasm I hope? If not, then why are you even here?
 
My wife heard it yesterday with a half tank of gas. Whoopee do.. It will not harm anything and I have heard this in much more expensive vehicles as well.

Enjoy your ride and think to yourself louder and it will be ok (nana)


I always have my 3rd row seat folded down with a Husky truck liner over the entire rear section. That must be why I never hear the sloshing sound....lots of insulation I guess.
 
yep, heard sloshing in the tank of gas when it was full. (now it's close to empty and i haven't heard it for awhile).

also noticed it on my wife's 06 mazda6 when we bought that 3 years ago

never heard it on my bmw...

i remember reading somewhere (don't know if it was here or somewhere else) that automakers put fins (?) into the gas tanks to reduce the sloshing around of gas?
 
What I heard over the weekend is not sloshing but rather slight splashing. The tank was between a 1/4 and 1/2 tank. I have heard (and felt) real sloshing and like I said, mine does a little splashing and I really had to listen for it.
 
Turn up the music volume. Easy fix.
Seriously, the sloshing is present if you try to hear it (with music volume down) when the tank is above nearly full (not full). I normally have music on so it does not bother me at all.
 
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