Overflowed Diesel Tank???

Weird thing happened today. Was about to hit the highway this morning for a 300km round trip to my son’s hockey games … drove a couple minutes down the road for my first fill up since picking up our new 2024 Diesel SLT XL just over 2 weeks ago.

Had between 1/3 and 1/2 a tank… after pumping barely 4 litres (1 gallon) the nozzle stopped fuelling… which doesn’t make sense given I have over 500km on this brand new tank. So I pull nozzle trigger again and the tank immediately starts overflowing and diesel spills all over. I thought maybe I misplaced the nozzle so I adjusted and gave one short pull, and same result. Overflowing. I pumped a total of just over 5 litres (1.33 gallons).

Fortunately, I had enough gas to drive the 300km trip we had today so I ran home, wiped all the diesel off the side of the truck, changed my shoes and off we went.

Later this afternoon got off the highway near our house and pumped a full tank of ~93L (25 gallons) at a different station. All good!

Just wondering, what the heck happened. Could it have been an air pocket? I can’t understand how this happened when I had less than half a tank of gas when I started pumping earlier this morning. This has never happened to me in 20+ years of filling my vehicles unless the tank was already full of course and I was trying to max fill or something which I don’t even do. This was however the first time filling up a Diesel vehicle.

I am guessing you didn't have the nozzle inserted all the way.

Padraig

Nothing unique about the diesel tank that makes it overflow more easily. Must’ve not been all the way or trying to pump at awkward angle. I’ve owned (gas) vehicles that would make the pump “cut-off”, sometimes multiple times and with every fill up. Likely because of a combination of particular tank design and strong plump flow.

Our tanks do not have a lid, but there are two valves. If you don't fully insert the gun into the tank, you open the first valve without opening the second. The resulting capacity is approximately 0.5 liters. and no further fuel flows. Most likely, the gun first opened the valve, then moved back a little, and the valve closed. I once had a gas station employee fill the tank to full without inserting the gun all the way. I arrived at the gas station with 1/5 left in the tank. And only 5 liters came in. I approach the car, and there is an astonished employee there, and fuel that is right under the neck of the external valve. I had to take the gun from him and push it all the way in, after which almost another 80 liters fit in perfectly)

Dearest fellow Diesel Tahoe/Yukon Drivers,

The flapper that automatically closes on the inlet of filler has fallen off inside of my Yukon. I don't have any idea how it happened, but my wife was trying to fill it up and it kept overflowing. When a person and the station saw she was having trouble, he noticed the problem. The flapper is sitting in the little chamber above the neck down to the tank. The flapper is loose and I don't know what to do about it except take it to the dealer and have them explain it. This should definitely be a warranty issue. Very strange. I will post when I have an answer.

mikentosh said:

Dearest fellow Diesel Tahoe/Yukon Drivers,

The flapper that automatically closes on the inlet of filler has fallen off inside of my Yukon. I don't have any idea how it happened, but my wife was trying to fill it up and it kept overflowing. When a person and the station saw she was having trouble, he noticed the problem. The flapper is sitting in the little chamber above the neck down to the tank. The flapper is loose and I don't know what to do about it except take it to the dealer and have them explain it. This should definitely be a warranty issue. Very strange. I will post when I have an answer.

Click to expand...

I took it to the dealer and they were definitely surprised and had never seen that before. They had to order an entire new filler assembly. I will update after it’s installed.

mikentosh said:

I took it to the dealer and they were definitely surprised and had never seen that before. They had to order an entire new filler assembly. I will update after it’s installed.

Click to expand...

It's amazing how many things dealers have never seen before...

Weird on the above flapper issue. Fyi, re: my issue I think you guys were right. I didn’t have the nozzle completely inserted. Haven’t had an issue since that random overflow (I’ve only had to fill up 3 times). I just make sure to give nozzle a firm, but gentle, push to make sure it’s fully in. Thanks!