Well, I always have ran a quart of motor oil in every fuel tank. Today I accidently put in 2 quarts, I though it would not hurt it. On my way through town, the RPMs dropped and The truck was a sled. so I turned around and headed for home. On the way home, I stopped and drained the fuel water seperator and the fuel was a dull greyish black. Fired it back up and it ran great for 10 sec. then stumbled and almost died, made it home and I cannot run over 2,000 Rpms without backfiring. Idles fine. but misses and stumbles under a load.
Tomorrow I plan on replacing the fuel filter and removing the fuel from the tank, and putting fresh in.
Any advice/ suggestions would be greatly appreciatd!
Thanks
Wheelo

 

I'm no pro here but is sounds like the oil sank straight to the bottom of the tank and lifted up to the pump w/out mixing. Was the oil placed into a full tank?

 

I would just replace the fuel filter and not worry about anything else until you see what happens after that.

 

Same here. The extra viscosity probably just finished plugging an already almost plugged filter.

 

Ding!


When I instill additives, it's always followed by a good washing if you will with some fuel from the pump (fill-up).

 

So I could get by with just replacing the fuel filter?
I can drain stuff out of the filter and the truck runs great, then it starts to sputter. I pray I can replace the filter and get by.
I never could see how 1/2 a gallon of oil in 25 gallons of fuel could almost kill the beast?
Thanks,
Wheelo

 

If the filter is almost plugged with fine sediment already, teh extra viscosity, or "thickness" of the oil could make it next to imposible to flow thru the filter medium. when you "drain" a little, you a are releasing the surface tension across teh filter medium, and it takes a minute to re-establish and clog up again.
replace the filter and it should be fine.

 

Like said before, your filter may have been in need of a change and the thick unmixed oil may be stopping flow.

Personally I would manually get as much of the oil out of the tank as possible.

One way (and again, I'm no expert here) Take off the fuel filter and dump everything out of it. Take off the bottom off the fuel filter, (water sensor unit that has a cannon plug) Take the whole thing off.

Then I would screw the filter back onto the block, w/out the bottom piece to the filter.

I would then find a clean oil pan to place under the truck and lots of towels.

Next I would use the lever on the lift pump and get crazy with it and push at least a gallon of fuel out. It will be a messy job because the fuel will pour out bottom of the fuel filter.

Get as much of the oil out ot the tank as possible, because oil is heavier than diesel fuel and sinks to the bottom of the tank and is the first to go up to your engine.

Then install a nice new fuel filter and all the items taken apart, prime.
Then find a steep incline and mix the oil into yout tank by driving back and forth.

TomD

 

What did I miss, I've run 207,000 plus mile in the last 3 years. Towing heavy loads, running hard off road and trying to race ricers everyday....

what does adding a quart oil accomplish in these dang farm trucks

Big

 

What He Said!!

 

Apple Juice!

 

I usually add stuff to a partial tank and then add the fuel. Then I drive it some to complete the mixing.

Edwin

 

what is the purpose of adding motor oil to the fuel? help with lubricity?

 

it helps with lubrication and i have herd it gives a little better fuel milage to.

 

its the fuel filter, cause i usually add 4 gallons of used oil to every fill up, yeah im running a 20/80 mix of oil/diesel. it seems to be fine, starts better, hazes at idle, smokes alot more, saves 12 bucks every fill up, all the good qualities i look for in my truck. i will be changing my filter in about 2 or 3 more tanks of fuel, so that will be a total of probably 50+ dollars in money savings and im helping get rid of waste oil so it isnt put into the water supply.