Wife put 26 gallons of gasoline in the 6.5

[914turboford]

My wife put 26 gallons of regular gasoline in the suburban while I was at the bank nearby. The pump shut off because it had reached $75. I added 6 more gallons of diesel. It ran rough and low powered over to Wal Mart where I added a quart of ATF. It wouldn't start so I dumped in a quart of Power Service. We let it sit for about 2 hours while we walked over to look at a 6.2 K10 we had been scheduled to see. When we came back it started and we drove it the 10 miles home with a 2000 ft. climb at speeds of 35 mph max. I would run decent up to about 1500 rpm and it idled nicely. What should I do now? Would it not run well because of the low cetane in gas? Should I dump in one or two more quarts of Power Service? Or do I have to drain that fuel mixture out? I was thinking maybe I could drain half of it and fill the other half back with diesel then poor it back in over time. But I'd like to avoid that unpleasant task if possible.
Brian

[Mark Rinker]

If it were me, I'd unhook the line from the pressure side of your lift pump, power the lift pump up, and pump everything out of the tank, re-filling with fresh #2 diesel.

[pgguru]

Gas In a diesel is nothing BUT BAD. Get it All out of your TANK. You should have had it towed. There is no Lubrication in Gas and you might have damaged the Pump and Other Parts.

[DmaxMaverick]

Sounds like you more than offset the lubricity loss of the gas, and increased the viscosity some with ATF and additive. Still, you must have had a significant amount of #2 in the tank. Any amount of gas more than about 25% can cause other issues in the combustion chamber, but there should be no worries of the fuel system. Unfortunately, all the gas in the tank is too contaminated to burn in a gasser vehicle, so what do you do with it? If it were me, I'd drain the entire contents of the tank and fill with fresh #2. Then, burn that concoction of gas/oil/additive in the Burb at about 10% until it's gone. If you live in cold country, it has an added bonus of helping with waxing/gelling problems. There was a time (quite recent, actually) gasoline was recommended by GM as an additive to help with freezing temps. There's no problem with getting gas in the fuel. The problem is how much. Gas has the same base (LPG to asphalt), just at a different location on the scale (or in the stack) with higher volatility, lower cetane and viscosity. Once you offset the lubrication and viscosity quality (necessary for the Stanadyne pump), it isn't harmful in small concentrations. I've ran 100's of gallons of gas through the o'l 85, and other Diesels I've had. Never a problem.

If this needs a repeat in the future, 2 stroke oil is a better alternative. ATF, contrary to old school belief, is a poor choice.

[rustyk]

I agree (being a reformed fuels and lube engineer). Get the gaso out of the tank. As mentioned, ATF isn't ideal, but it's serviceable as a lube. Overtreat the tank the next couple of refills with 2-cycle oil (around 4 oz./10 gal).

[Cowracer]

Based on my real world experience, I doubt your motor will live. It may run (for now), but due to the extreme combustion pressures caused by the quick igntition of the gasoline, you probably have damaged the block, rods, head gaskets, piston tops, or all the above.

Your engine at the higher speeds was advancing the injection point of the gas enough that it combusted well before tdc, and the resulting peak pressure (the expanding combustion gasses) coupled with the continuation of compression most likely lead to some catastrophic combustion pressures (and temps).

I wish you luck, but I dont think this will have a happy ending. At least not one that comes out of a bottle.

tim

[sturgeon-phish]

A similar thing happened to me several years back. From fill up with gas drove about 2 miles and from idle the truck died. When it would not restart I popped the hood and vented the fuel filter and smelled gas! Drained tank completely then filled with 32 oz. of diesel conditioner and fresh diesel fuel. Gave away the gas, used it in mowers and tractors. Was not worth the potiential damage running gas however treated in a diesel
Jim

[Robyn]

In my tenure with the 6.2/6.5 engines I have seen 3 filled with gas.
As has been mentioned, pump the stuff out and refill the tank with #2

Run the pump a little more to get the system filled with #2 again and start it up. It should run ok.

The worst case scenario will be an IP overhaul.

If I were you I would give your wife a lovely bouquet of flowers and a nice note attached that suggests love and kisses. I would also ask her to never do the gas in the diesel thing again or if she does to not call you but just handle it.

Or you may want to tape a two foot square sign to the side of the truck that reads DIESEL ONLY

This will probably get you some nasty looks but this is not a very forgiveable mistake and can be costly to fix.

The chances that there was internal damage to the engine itself are remote as long as there has been no other signs.

best

Robyn

[914turboford]

Thank you for the replies. I drained about 37 gallons of the concoction out. Drove it to the fuel station (at about 10mph) and filled it with diesel. We then drove it on a 20 mile round trip and it seems to be back to normal. I'll let you know if anything bad happens in the near future.

[Fumes]

Is it still running??