How Long to Soak Oil Pickup in Kerosene ?

Unless you have been desludging regularly you run the risk of dislodging a bunch of gunk that doesn't exit the drain but clogs an oil passage somewhere when you fire the engine up. It is an even bigger problem on a motor that has endured a long period of deferred maintenance.

When I have done this sort of thing, I let them stand overnight, so 12-24 hours roughly.

I have heard the old caveat about dislodging something that may plug the engine oil passages, but have never personally had it happen. (That is not to say it CAN'T, but I have never experienced it.)

I would have enough kerosene handy that I could give it another shot or two after I take the drain plug out...I would flush it until it runs clean (not necessarily colorless, but certainly clean).

Now, I have seen crappy old engines where someone did some nasty shadetree work, and left bits of gasket scrapings and such in the engine. If you have that in your filter screen, nothing will take it out but physical cleaning.

Once I put in new oil, I would run it until it got up to full temperature. Then, drain it while it is still warm.

I would not do this. Even if you break up the sludge, where do you think it will end up? You are asking for more problems than the car has now. If it is that bad, it needs a motor.

Not necessarily. Right now I'm working on a '55 Stude with a '63 Stude V-8 in it. There's a horrific amount of sludge in the engine but the darn thing runs like a top and pulls like a freight train. It'll bark the tires from a dead stop, even with a 2nd-gear-start automatic transmixer, 3.31:1 rear end and no brake-torquing. Of course, I'll be pulling it as soon as the weather gets nice and manually cleaning the insides (currently resisting the temptation to pull the heads off and have them machined for larger valves...) mostly because the oil pan gasket and front main seal are leaking badly and pissing me off, and it'd be dumb to have the pan off and not clean it out.

Which prompts another question; can I use carb cleaner for this task? Or is that potentially harmful to the bearings and I should stick to kero?

nate

Carb cleaner is really hard on rubber parts, gaskets, o-rings, etc. It is a hell of a degreaser, but I wouldn't use it if I weren't going to disassemble the engine.

I always did that. Or just a cloth with a little xylene on it, and a lot of elbow grease. The carb cleaner is going to evaporate pretty fast and won't hurt anything.

That said, I think the best thing to do if you don't have a catastrophic problem is to use an oil with very high detergent and solvent actions. Change every 3,000 miles, and after a dozen oil changes you'll find most of that crap has been flushed out.

--scott

I am going to disassemble the engine, but I'm specifically concerned about the bearings as I wasn't going to bother removing the crank or pistons. (or take the heads off for that matter) All of the gaskets and seals are pretty much shot anyway, which is the whole purpose of this exercise.

Actually, come to think of it, will carb cleaner dissolve Glyptal? If it does I won't bother, as Studebaker blocks were all factory coated with Glyptal inside, which I'd like to preserve.

nate

If this engine runs good now, and you plan to only re-seal the leaks; why take a chance with any chemicals or solvents in the pan? Carb cleaner is nasty and might remove that glyptal, and other items you'd like to save.

My brother in law was saying similar things using diesel. I wonder which has more viscosity and detergent? He flushes old cars by filling with diesel and idling for 5 minutes or so then drains and refills with fresh oil. He says it works good and has caused him no damage. I am slightly skeptical.....

Bob

One of the things you look for is a solvent that is good enough to take out the sludge, but not so good as to destroy the gaskets and rubber parts. Kerosene and diesel are reasonable candidates for this.

Neither one will give you any any substantial lubrication. You may not do a lot of damage(due to loss of lubrication) idling for a minute or two this way, but most of us would be hesitant to do it.

Could change the oil & filter, add a pint of Marvel Mystery Oil to the new engine oil and run it a bit (maybe couple hundred miles) then change oil and filter again -- but be careful it'll attack sludge everywhere so don't overdo it!

Kero/Diesel is a semi-decent lubricant, but it's way too thin to run a car engine on. But at no load it is probably safe.

nate

I figured the same, Nate, but you know how it is here. If you don't give the appropriate caveats, people jump all over you for recommending something they consider to be damaging.

I wonder how many people who have posted about plugging the engine after such a treatment have ever actually encountered the problem? I would bet few if any. There is so much urban legend hearsay out there that people believe things as fact that they have never experienced.

Is that how you would describe the guy who reads too much but does too little, to be useful? s

There is a strong point for 'book learning' and a powerful advantage in experience. Putting them both together gives a person the opportunity to be an expert in what he does.

Passing along, as true, what he or she has only heard others say can lead to problems. I think we all accept as fact things not in evidence from time to time.