Gas in Diesel tank :-(

[gpm]

2019 Newmar Dutch Star 3717 on a Frieghtliner with 450HP Cummins. Tank was approximately 3/4 full. Erroneously wife pumped approximately 6 gallons of gas in the 100-gallon diesel tank. I topped it off the remainder with diesel and drove it approximately 10 miles home with no issues. Will the 94/6 diesel to gas ration be ok to continue to drive or will I have issues? If so, what can I expect to see? Remedy? Approximate cost? Thank you!

[BonS]

Diesel fuel is heavier than gasoline. The fuel pickup is near the bottom of the tank. So, you will be drawing diesel fuel until the overall level drops and start pulling gasoline. You will do great damage to your engine if this happens. The correct thing to do is to stop running your engine until you get your tank drained. Gas and diesel don't mix. You're certainly not the first to have done this.

Here's a link to someone that just went through the process.

[hamm2018]

Call Cummins and inquire. Gas in diesel is not good.

[jaydee325]

Originally Posted by hamm2018

Call Cummins and inquire. Gas in diesel is not good.

Agree.

As an aside, way back, Chevrolet had just started offering a diesel option in their pickups. I was at the local Chevy dealer talking to a couple of my friends who were sales men there and one of them had just sold one of the diesels.

The sales man was waiting for the prep guy to return from filling the tank with fuel so he could deliver it that afternoon. We were standing in the front of the showroom that had floor to ceiling glass. As the truck pulled up, it sounded like someone was throwing handfuls of marbles at the glass. The sales man shouted an expletive and ran out the door hollering "shut it off"!

Was an expensive oops for the dealer as Chevy wouldn't warranty the needed repairs.

[Ludo]

94:6 is no problem, at half full refill with diesel and repeat this procedure 2 or 3 more times. If you're anxious do it at 3/4 ��

[Alpine36]

Shouldn’t be a problem. As mentioned, keep filling the tank when it reaches 3/4.

[shootist]

Really surprised in the video that they didn’t have a 12 volt transfer pump, crazy draining all that fuel 4 gallons at a time. I would have loaded it up with a lubricisity additive and run it. She was fortunate that they got the water out of the tank.

[Newmar2856]

I wouldn’t drive it anymore or even turn it on until you can get the tank pumped out and cleaned. The high pressure fuel systems on a modern diesel don’t tolerate contaminated fuel well at all. I only hope no damage has been done yet. The repair if gas has gotten into the fuel system is going to be costly. I’d call a Freightliner shop and your insurance company right away.

Sorry this happened to you both.

[Ray,IN]

Originally Posted by Ludo

94:6 is no problem, at half full refill with diesel and repeat this procedure 2 or 3 more times. If you're anxious do it at 3/4 ��

I agree, keep; the tank topped off with diesel. Back before winter-blend diesel fuel came into being, truckers used to add gas to their diesel fuel to prevent gelling.
I would also add lubricity additive to the tank JIC.

[Ludo]

Instead of additive you can add a quart of 5w30 oil. But it's really not necessary in this case.

[Newmar2856]

Please call Frieightliner or cummins and I just can’t get behind others that are saying just keep topping it off with diesel or add oil. This is a modern diesel engine. The old engines without any of the emissions systems were tanks. Not so anymore.

[bubby124]

If gas is lighter than deisal cant he just siphon out the top 20 gallons and get most of it out

[Toribk]

Concur with Newmar 2856. Call Cummins, the manufacturer of both the engine and the aftertreatment system and get their recommendation.

You will certainly not be the first person that they have consulted on this issue.

Call 1-800-CUMMINS

Please get back to us on their recommendation.

[Wbago97]

I'm not a mechanic and never even owned a diesel, but even though gas is lighter it would eventually mix with diesel, not just stay at the top.