john deere 6068

[kdk]

would running a John Deere 6068 with a mixture of gas and diesel cause a valve to drop into the cylinder ? It is important to note that after disassemble and inspection, no other cylinders or valves are affected. Only the number 1 cylinder was affected.

 

[Billrog]

Wouldn't effect your motor but not very healthy for your injection pump.

 

[Birken Vogt]

The old Ford IDI models that used a similar injection system, but not a real similar engine, had in the manual that it was allowable to run on up to 30% gasoline or some such amount.

I doubt it had anything to do with it.

 

[partsandservice]

Cam lobe failure . Mis adjusted/ no valve lash maintenance . Valve guide failure. I am not qualified to answer the gas mixture question, but pre detonation can absolutely create clylinder damage possibly overheating the valve??

 

[mg2361]

Welcome to HEF kdk! How long did the engine run with the gas? Was the valve failure at the top at the keepers or did the valve head come off? Pictures? 1% gasoline in diesel can lower the flash point by 18° C (65° F). With the associated premature ignition that would lead to engine damage not to mention possible injection pump/injector damage since diesel fuel is an oil and lubricates and gasoline is a solvent.

 

[Vetech63]

OK I have never heard of running a diesel engine on a gas/diesel mixture. The flame out in the cylinders must be pretty severe I would think. Pre-detonation is an understatement in this case!

 

[highwayghost]

I'm kind of an old timer and have heard of gas/diesel mixing years ago, mostly only for cold weather running. If I remember correctly it was at 10 % or less gas added. I can see how it could have benefited in cold weather starting/running or help a tired/worn engine. With the advancements in engines, fuels, and the availability of quality fuel additives I've not heard of anyone using this lately. These are not the engines of years ago. Not your "Fathers Buick" so to speak! With expense involved of repairs these days, I find it's best to play it safe and follow manufacture recommendations. Did anyone ever see a dealer manual that recommended fuel mixing? Even from 'back in the day'?

 

[Birken Vogt]

Did anyone ever see a dealer manual that recommended fuel mixing? Even from 'back in the day'?

The old Ford 6.9 pickup engine manual was where I saw it, Stanadyne injector pump similar to JD and a lot weaker engine inside than a 6068.

 

[thepumpguysc]

Yes, I had a service bull. that states 10% max in a Bosch fuel system.

 

[Trashman]

I have a guy that was putting aviation fuel in a diesel tractor. He thought it made the tractor run better.

 

[thepumpguysc]

it dam sure will.!!
But theres no lubrication properties in JP fuel & it wears out parts that arent made to wear out..
If he has pump problems, ask him how much he paid to get it fixed.??

 

[kdk]

Gentleman the fuel mixture was not done intentionally it was a supposed error the engine dropped number 1 valve .

 

[thepumpguysc]

WHERE was the "breakage" ?
at the keepers.??
& depending on the amount of gas that was pumped & the size of the tank & how full it was to start with would determine if any damage was done due to the fo'pa..

 

[Vetech63]

Take a pic of the broken valve, the valve seat, and the piston top. Pictures will help.

 

[Tenwheeler]

It would damage the pistons from over heating before it damaged a valve. Just my opinion but I have seen an NTC with galded pistons and gas in the tank.