Archived Help- Gasoline in diesel tanks!!!

[RNixon]

Help! Please.



My brother just called. He was using a diesel pickup borrowed from a relative, and mistakenly put some gasoline in it. Pickup has two fuel tanks, and he put gas in _both tanks_. He drove the truck a short distance before realizing what he had done. He did not notice any immediate very bad effects. That surprised me. I thought it would immediately do terrible things to the engine. But maybe the gasoline is floating on top of a layer of diesel, or something like that.



Need to know what all to do. I told him NOT to start the engine again under ANY circumstances. If I understand correctly, he will have to completely drain the tanks and get every drop of gasoline out, even if that means pulling the tanks out of the truck.



What else beyond that?? I've never known anyone who did this, but have been warned of dire consequences if I ever did it.



Thanks, everyone.



Rob kd5bxz

 

[Hoefler]

Drain all the gas out and change the fuel filter. A trace amount of gas should not bother it. Good luck

 

[Swamp Donkey]

I am no expert on this, but depending on how much gasoline he put in would be how concerned I would be. With the info I have I would suggest draining the tank as far down with a siphon hose. Not every drop has to come out. By the time the tank is refilled, the ratio of gas to diesel should be really low. I would also strongly recommend adding lots of diesel fuel conditioner. The more, the better. 3-4 times the recomended dosage. 10 or 20 times... ... ... it won't hurt a thing, and can only help in the lubrication of everything. This is what I would do. Hope it is good advice!

 

[RNixon]

Got some more information now. Before he filled the tanks, they were low. Less than 1/4, so not much diesel to dilute the gasoline. He drove it home after filling, but did not notice any smoke from exhaust or oil blown out of engine. He did notice some knocking and rough running, so gasoline definitely all the way through fuel system and into engine. I learned that gasoline will mix with diesel, not separate and float on top, so this engine got a pretty good dose of gasoline.



Also talked with my good friend Greg, who ran a diesel repair shop for years, and now works for a county precinct that uses a lot of diesel vehicles, from pickups all the way up to heavy construction equipment. They have this happen a few times each year, so he is very familiar with the problem. His advice is to take to a good, experienced diesel shop or dealer and have them remove and completely drain fuel tanks, disconnect and drain all fuel lines, replace all fuel filters. Also change oil and filter. After that, refill with diesel with lots of fuel conditioner/lubricant.



Another thing to worry about is excess wear on rings and cylinder liners from loss of lubrication that diesel provides. Greg says what often happens to their diesel engines after running on gasoline, even fairly briefly, is they may start burning oil due to ring and cylinder wear. All you can do is clean out the system and see how it turns out.



How does this square with what you guys know about this? I'm seeing a range of suggestions.

 

[E7mack96]

Just last week, a new hire accidently put 30 gallons of unleaded in one of my trucks. (it holds 100 gals) I had him top off with #2 then and there, and top off 2 more times through the day. It seems just fine so far.



In your case, I'd drain the fuel/gas mix. I'd then change filters. Then, I'd dump in some power service silver bottle double the dose, and top off with good ole #2. Dependinf on make/year, maybe crack injectors as someone cranks engine to bleed off gas mix.



It should come out ok.

 

[DSpencer]

Do a search on gasoline. It seems that its lack of lubricity is the worst problem. Your injector pump does not like it.

I would drain as much of it as I could. Sounds like as much gasoline as you have you could still use it in a gasser. They can take diesel better than a diesel takes gas. I would also add a good dose of additive or gallon or so of cooking oil for lubricity.

 

[MMeier]

What type of truck is this we are talking about?? I would just siphon out what I could and then top off and add a good dose of Lucas or the like. When I had my 12 v trucks if I was filling fuel jugs and had a gallon or two left to go I would just add it to the tank and let it go, never hurt a thing!

 

[RNixon]

There are a couple more threads here about this topic. I'm seeing a wide range of opinions. All the way from just siphoning out as much as possible of the gas and refilling, all the way to pulling off the tanks for complete emptying and blowing out all fuel lines, filters, etc. I'm still confused about the real implications. Most serious potential problem I'm picking up is damage to injection pump and cylinders from loss of lubrication.



This truck is a powerstroke, and I found some informaton indicating that those have higher compression than Cummins, and this more potential for damage from gasoline. Not completely sure about that.



Since this truck does not belong to my brother, and he does not do his own mechanic work, it seems like he may be better off to take the truck to a dealer and have them do the work. If it was my own Cummins engine, I would probably drain tanks myself, clear fuel lines as much as practical, replace filter, add a bunch of lubricant / fuel conditioner, refill and hope for the best.



At this point, I'm giving a lot of credibility to my friend Greg, who has worked full time on every kind of diesel engine there is for many years, and has surely forgotten more about diesels than I will ever know. His advice was to remove and completely empty tanks, drain fuel system lines, replace fuel filter, change oil and filter, then refuel and hope that no serious damage was done to injection pump, rings and cylinder walls. No guarantees even after all that.



I'll talk to my brother again later today or tomorrow and see what he decided to do.

 

[DieselMinded]

Borrowed from somewhere??? I forget where I got it . .



Mixing Gasoline with Diesel Fuel



At one time information was released suggesting that a small amount of gasoline mixed with diesel fuel for use in cold weather was an acceptable practice. This information was eventually retracted due to conditions that may result from such a mixture.



First and foremost is a safety factor. The gasoline fumes from gasoline are very rich and there is not enough oxygen available for a spark generated at the filler neck to ignite these fumes. The diesel fumes are too lean and will not ignite. A mixture in the right proportion could create fumes volatile enough to ignite from a spark generated at the filler neck.



Second, all injection pumps and injectors utilize the lubrication in diesel fuel to keep internal parts lubricated. Gasoline cuts down on this lubrication and can lead to premature injector and pump wear or even failure.



Although accidentally mixing a small percentage of gasoline with a tank of diesel fuel may not result in an immediate problem, it could still result in shorter pump and/or injector life. The only safe action would be to drain the mixture and start from scratch. While this may seem costly, it could save you from more costly repairs in the long run.

 

[RNixon]

Just to wrap this up. This truck was towed to a dealer for service. The dealer drained the tank and all the fuel system and lines completely, replaced fuel filter, changed the oil, and the truck is back running. So far, the engine is performing normally, and they have not noticed any residual problems. The dealer repairs were covered by insurance under the comprehensive policy coverage.

 

[GarrettPetersen]

Drain the tanks the best you can by hookin a pump to the suction line from the tank. put a gallon of oil in each tank and a couple bottles of fuel conditioner in each tank. Fill em up with diesel. change the fuel filter and drain the bowel and fill the bowel with fuel conditioner and thenstart the truck and hope for the best. good luck. I deal with gas in the diesel alot through out the year. 99% of them everything turns out just fine and dandy.