Motor oil in fuel tank??? - PeachParts Mercedes-Benz Forum

Gordinho80 · #1 10-02-2004, 11:15 PM

i was told that adding a quart of motor oil to the fuel tank is good for the fuel system...yay or nay?

thanks...

Gilly · #2 10-02-2004, 11:24 PM

Nay on a gasser, at least one with a catalytic converter.
Diesel, eh maybe. I heard ATF, not motor oil.
Gilly

Gordinho80 · #3 10-02-2004, 11:28 PM

show i should be able to add a quart of ATF fluid to my diesel tank and it will help the fuel system???

MTUpower · #4 10-02-2004, 11:28 PM

do a search- there was just a thread on this exact subject not a month old. I put motor oil in my fuel tank (up to 35%) (617-912) and it runs great and is very quiet. A bit of smoke and stinky compared to straight diesel, but runs fine. Veg oil into the fuel tank emit no smoke, smells great and runs fine. :p

Gordinho80 · #5 10-03-2004, 12:34 AM

is there any power increase or decrease with either the motor oil or veg oil in fuel tank?

tomm9298 · #6 10-03-2004, 07:00 AM

I run 1 gallon of WVO (waste vegetable oil) per tank full. I have not noticed a power increase. Yet it is a good way to lube the fuel system. And the exhaust smells like McDonalds!!! Prior to this, running WVO for about a month, I added 2 stroke motor oil, 1 quart, in a full tank. WVO smells better and I get it FREE!!!!

bill murrow · #7 10-03-2004, 08:31 AM

I've heard of folks using wvo, motor oil, and 2 stroke oil in a 50/50 mix with diesel. Won't work under air temp of 50f. I guess it gels or something.

I've been running both 2 stroke oil[left over from a long sold boat] and old motor oil [not used oil] in mine. Probably about a gallon of each.

Used motor oil I've heard ok if filtered to 5 microns or less. Never tried it myself...

Cheers,

Bill

tomm9298 · #8 10-03-2004, 04:40 PM

I have not tried this, but I will unless some veteran advises against it. But, a few years ago a long haul trucker I know said in winter he adds kerosene to his fuel to keep it thin. I will start lean, maybe 1 gallon per tank full.

Murkybenz · #9 09-25-2010, 07:22 AM

Quote:

Originally Posted by tomm9298

I run 1 gallon of WVO (waste vegetable oil) per tank full. I have not noticed a power increase. Yet it is a good way to lube the fuel system. And the exhaust smells like McDonalds!!! Prior to this, running WVO for about a month, I added 2 stroke motor oil, 1 quart, in a full tank. WVO smells better and I get it FREE!!!!

Up the veg to 30% and there will be a difference.

It is best to mix it out of the car before putting in the tank,if it has to travel around the fuel system to get mixed it takes longer to notice the effect.

My previous car was a Bmw 525tds turbo inter cooled diesel 1994,anything over 30% veg gave no extra power.The 30% seemed the optimum mix with diesel .

You will notice a bit more zip,not much but the engine will be a bit more eager to rev.

On the Bmw which was all edc controlled fly by wire the veg mix would be noticeable in firmer gear changes on the auto box depending on how much percentage of veg added.

The veg giving more energy see's less throttle pedal for a given speed so the ecu would sometimes see up to 1/2 inch or less pedal position and this coupled with the ecu controlled gear box resulted in firmer shifts.

The Bmw would lock up into 5th gear and cruise along ticking over at 1800rpm around 80mph,approaching an incline it would just drop itself down into 4th gear to hold the speed and then over the top and on the level would lock back into 5th.

The added veg would see it hold 5th longer or not change down at all.

Towing a heavy trailer this was a bonus as more often than not it would only go into 5th on a down hill stretch using only diesel,so the 'less pedal position' fooled the ecu into thinking the engine was not working to hard and it would go into 5th .

vtmbz · #10 09-25-2010, 07:40 AM

Kerosene is commonly used in northern climates to replace #2 (diesel) because at temperatures below -30deg f, it will not gel. Notice I said -30deg f. You should not have to add kero in SC ever. Just for the record, it costs more than #2, and is not as efficient.

Unless you are a meticulous, obsessive/compulsive person you should stick with the fuel that God meant MB to use- undyed diesel from the pump. This forum is filled with instances of people buying old diesels and then subsequently posting that the cars "wont start", "run rough", or are dying along the road. Its a shame to read about. For the price of a new injector pump, the smell of french fries is a large price to pay... it seems like the primary killer might be technique-- ie, how you treat your "free" oil before dumping it in the tank. So before you leave the fuel distribution system behind, make sure you are set up to do this.

JHZR2 · #11 09-25-2010, 11:51 AM

Quote:

Originally Posted by Murkybenz

Up the veg to 30% and there will be a difference.

It is best to mix it out of the car before putting in the tank,if it has to travel around the fuel system to get mixed it takes longer to notice the effect.

My previous car was a Bmw 525tds turbo inter cooled diesel 1994,anything over 30% veg gave no extra power.The 30% seemed the optimum mix with diesel .

You will notice a bit more zip,not much but the engine will be a bit more eager to rev.

WVO and biodiesel both have LESS ENERGY CONTENT per kg or liter, so it is not really possible to make more power using it. Most any effect is placebo or some minor effect due to some feel that cannot really be there.

Have any dyno runs to show more power on WVO?

SD300 · #12 04-11-2010, 12:11 PM

A dude is using used ATF to run in his SD, for 2 yrs no issues except not clean enuf to pass Smog test in BC.
He filters down to 25 or more micron, usinf filter paper so is not so fine.
I got some from him and going to try it out.

69shovlhed · #13 04-11-2010, 11:02 PM

some of the MB mechanics i know are running alot of atf in their cars w/ no real problems, used dirty atf. the only problem seems to be filters need to be changed more often. i told them to filter it first, at least thru an old tshirt. i tried filtering it that way and it does get some of the dirt out. i wouldn't run it straight though.

SD300 · #14 09-24-2010, 09:03 PM

I am running filtered used ATF , using a 10 mic filter bag.
Used vege oil using 1 mic filter bag, my buddy as a long vacuum filter bag in it, so some of the dirt get caught in the vac bag, cut down the washing frequency.

Any folks out there using filter used motor oil?
I can access to plenty of them, one garage I knew he said the recycle guy only pays SFA for them, so I can take, drink as much as I want.

I suppose mixing 10% of used motor oil may not be all that bad.
My cars are not going to last forever anyways, only Taxidermy does.

Junkman · #15 09-24-2010, 09:30 PM

This is discussed endlessly on the 2nd gen Dodge Ram forums with the expensive and $1,000 problem prone VP44 injection pump. I recently had to replace my VP then the new one crapped out within 100 mi. I figured that it was because of a bad rebuild then the rebuilder called & said i had gas in my returned under warranty pump. Gas (if it was actually gas) was from the diesel pump.

The above led me to pay more attention to fuel lubricity. One forum where the owner actually does some research & testing recommends 1 oz of 2-stroke oil/gal of diesel. The reseller of my VP recommends "Stanadyne Lubricity" saying that he's talked to the Stanadyne rep and looked at injectors run with & without the Lubricity. At recommended dosage & $20/ 1/2 gal, it is cheaper that 2-stroke.

FWIW, the SD runs quieter on either 2-stroke or Stanadyne Lubricity than fuel only. The Lubricity has to be bought online or from a local diesel performance vendor. The 85SD owners manual recommends some portion kerosene in the winter but that was before ULSD. I'm going to stick with Stanadyne since I need it for the VP.