DEF tank?

 

its the thump that would be an issue for me, the fuel pump riding the wave of sloshing fuel lol

 

My truck does it. I was worried thinking it was clunking somewhere. Come to find out its the fuel in the tank. Oddly enough now that i know what it is i never hear it anymore.

 

So I purchased a 2017 Canyon Duramax SLT 4x4 Short Box a month ago. The truck has 2000km on it right now. There is a strange thump, sloshing type of sound coming from the back of the truck. The sound is present during a quick stop and typical happens 2 seconds after a full stop - it's delayed. The sound is mostly noticeable on a full tank of gas... however you can still hear it when the tank is half. Took it to the dealership today, they don't know what's wrong, but ordered a replacement fuel tank... to see if it's going to fix the problem. Otherwise they have to start taking the truck apart..... I told them it might he the baffle, but they mentioned to me "if it is the baffle you would not hear it on a full tank, the sound would be present close to empty / half tank".

Very puzzled what's going on...

I noticed this too when my truck was parked on the curb ( and the reason I mention that it's because the curb off the street had a lean) and when I pulled off and did a u-turn, I heard water moving around, and then I moved to a house with a flat driveway where I pull straight off, I haven't heard it.

Didn't even notice the sound was gone until you mentioned it.


sooo... maybe it has ballast tanks, and once the ballast even out in the tank, the sound is gone?

I know we're all smart people, but in case one is a office fella - A ballast is meant to keep the water from splooshing around end to end, the ballast are dividers that divide the tanks into sections while still allowing free flow.

Watertank without the shell

 

i thought it would be baffles.

 

Update

Hey all,

[2017-12-15]
New fuel tank arrived - delivered the Canyon to the dealership this morning. Took them about 6 hours to replace the fuel tank. They gave me a Silverado to drive around in the meantime. When I picked up my Canyon from the dealership I drove it straight to the gas station, filled up the tank and prayed the sound would not be present... The first hard stop I did - 2 seconds later a loud thump came... The issue is not fixed. I drove it around a couple of blocks afterward...testing it by hard breaking - the thump was present all the time. Called back the dealership, it seems like they do not know whats going on, nor what the problem might be, they told me they will do more digging before calling me back.

 

I asked the dealership if this is normal. They said it is not.

 

2018 SLT does exactly the same -- thought I'd been rear-ended at a light! A *little* bothersone having that much weight shifting around like loose cargo.

 

I hear those noises all the time in 92A TDIs. DEF slosh.

 

They took baffles out to save money ..My 1998 silverado did it they replaced the tank and new one did it..There is 170 pds of gas hitting back/forth....If no baffles you will get this most likely is your problem..

 

I've never noticed this in my 2017