Question for car guys-Diesel fuel in crankcase?

[SEIndSAM]

I just saw something I have never seen before. Was at my local BP getting my morning Diet Pepsi when the guy in front of me in line pays for $1 worth of diesel fuel. I watch what he is doing and it puts the fuel into the oil fill on a 96-98 Dodge Caravan. Any ideas what he was trying to do?????

I that an old time oil flush or something????

 

[Noland]

He is probably doing a flush before changing the oil. I have known people to use kerosene too. I think it is a bad idea.

A good heavy duty engine oil like Rotella does a good job of cleaning and it provides better lube properties than diluted motor oil.

 

[db1959]

My grandpa used to put a quart of kerosine in the oil before he changed it. He'd let it run at idle for about 15 minutes. he would save the used oil and when he had enough he would dump it in the dirt driveway to kept dust down. Of course us kids used to make "tar" balls and throw them at each other. This was back in 60's and early 70's. He swore by it but he was about as "old School" as one could get.

 

[kevman65]

With the properties of OLDER oil it was used to thin the oil and help break loose sludge before oil changes.

With properties of NEW oil it is not needed.

You can also put a quart of transmission fluid in to loosen up the sludge and thick oil, and you'll smoke like a powerhouse. This too is no longer needed.

 

[Mr Evilwrench]

If he has some sludge the diesel is a good solvent for that. I've used it myself, just filled the engine, disconnected the ignition, cranked it a few seconds every day, then drained it and filled the oil. Much better.

 

[rotortech]

Like others have said - engine flush. I have used 50/50 Automatic Trans fluid and oil, but only in the case where the owner never changed the oil in 60,000 miles. That engine was really a mess and I was able to clean it up this way. Except for extreme cases of neglect, I see no reason for running this kind of flush. As stated above, modern motor oils keep things very clean inside the engine. Just need to change it now and then.

 

[jblomenberg16]

Sounds like he was trying to destroy his engine. Engine flush aside, fuel dilluted in engine oil means the engine oil does not lubricate as effectively as it is supposed to. That means that running the engine under any appreciable load and for any amount of time will likely cause damage to the main and rod bearings. Damaged main and rod bearings means the engine will go bye-bye in short order.

In short...DON'T DO IT!

 

[tmccorkel]

+1 on the engine clean. Diesel contains detergents, whch helps break down oil sludge. It very similar to the engine flush you can buy in auto stores. I wouldn't go on a road trip with it in the engine, but some in town driving wouldn't hurt much (also depends on the amount added)

 

[sepe]

Sounds like he was trying to destroy his engine. Engine flush aside, fuel dilluted in engine oil means the engine oil does not lubricate as effectively as it is supposed to. That means that running the engine under any appreciable load and for any amount of time will likely cause damage to the main and rod bearings. Damaged main and rod bearings means the engine will go bye-bye in short order.

In short...DON'T DO IT!

I've seen a Chevy van with a 350 run for 15 minutes with no oil at all. It was at a car show and was some $1 a guess kind of thing. After it started making funny noises and died, they let it cool down and filled it with fresh oil. They started it back up (took a couple attempts) but it ran ok. They tried it again and after 20 minutes they just gave up. Never did ruin that motor. Probably some bearing damage but the motor isn't always bye-bye as quick as people think.

 

[Mr Evilwrench]

You don't "run" it with the diesel fuel or whatever "instead" of the oil, you just put that in there to flush stuff out, then when you've drained it, you put in a batch of proper oil. You'll want to cycle it some to flush the crap out of all the little corners, but you don't drive it more than a couple of blocks that way. What I've done, is put the diesel in the engine in the driveway, and crank it a few times over a week, then drain it.

 

[IndyBeerman]

$1.00 for some diesel fuel is about a quart, and even though today's oils do not sludge up the engine like they used to, it is still good for a nice 15-20 minute run to let the detergents in the diesel fuel to do it's job of thoroughly cleaning the engine.

Growing up and working on cars like I used to, if you used Kendell Oil, when you removed the valve covers you would see some serious crud on the top of the head and covers.

 

[jblomenberg16]

I've looked a lot of engine that have run with diesel diluted in the engine oil. It does a good job of cleaning stuff out, that is for certain, but is also a great way to hurt you engine. My is that the fuel dillution will hurt it a lot worse than any of the sludge will.

And by the way, once that sludge is broken free, where does it go? It goes all throught the engine of course before it makes its way to the sump, and then to the oil filter.

 

[Don]

Incase anyone here don't know DIESEL is OIL. It is not some magical solvent.

 

[jblomenberg16]

Incase anyone here don't know DIESEL is OIL. It is not some magical solvent.

Say more. Aside from coming from similar crude stocks, #2 Diesel and Engine Lubricating Oil are very different.


And, yes, diesel has a lot of additional additives in it that make it a very nice solvent of sorts when it comes to breaking down heavier petroleum chains. Especially bio-diesel.

 

[Ogre]

Incase anyone here don't know DIESEL is OIL. It is not some magical solvent.

Currently available ULSD (ultra low sulfer diesel) has very little lubrication properties. I wouldn't put straight #2 in my crankcase for anything. In fact the early years of duramaxes have alot of issues because the injectors fail and allow #2 to infiltrate and fill the crankcase and more or less thin out the oil you have and cause huge problems...