Old Time Engine Flush - ATF in Oil?

I was talking with my Granddad the other day about working on the jeep and we started talking about how in the "old days" they used to run a little ATF in an engine to clean (aka flush) it out. He said that ATF had more cleaning properties than oil and that with 160k on my engine it might be a good idea.

He suggested that before my next oil change I drive it around and get it nice and hot, (normal hot not excessive) then let a quart of oil drain out, (not a problem since I have a leak somewhere.)

Next add 1 qt of ATF to the oil, crank it and let it run for a few mins then shut it off. Immediately drain all the oil as I normally would. Presto he said, it will clean the inside of the engine.

Now perhaps this worked 40 years ago, but what about now a days? Then again my Jeep is 20 years old so maybe this old methodology works for it. Has anyone ever done this? Seems like a good idea and perhaps just as good as some of those snake oil things.

I have talked to a couple old timers that have used ATF to flush an engine. I would recomend SeaFoam. There are countless threads on here about it. After using it on my XJ, I now put it in all of my cars. It has done wonders. I used it in the crankcase to clean out a lot of the engine gunk, with 200K there was a lot. Worked great. 6 ounces in the crankcase, run it for a few thousand miles and change. I did it a few times and it really cleaned out the engine. Even stopped some of the minor oil leaks I had.

added a qt and ran it for about 100 miles before i changed it, alot of crud looked like it came out. theres a thread on here somewhere that talks about this. i think it said the best is like 300-500 miles with atf, then change oil.

Yeah it was my thread I got too much help so I will pass on this help to you lol

http://www.naxja.org/forum/showthread.php?t=951884&highlight=cleaning+the+rockers

I tired the diesel technique with lil results. Seafoam did work great for mine.

I put a pint of kerosene in mine in the morning before I change it in the afternoon. Sea foam works too, so does the engine flush stuff. I have heard that the Atf really does a good job in the head too.

All these are are heavy solvents that dissolve carbon and sludge buildups.

Does it worry you guy's that the crap may break loose and begin clogging you oil pump screen?

FordGuy said:

Does it worry you guy's that the crap may break loose and begin clogging you oil pump screen?

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i dont think it will break loose any big chunks. it works by breaking down the built-up crap.

i'm more concerned with the motor-flush stuff and kerosene. they are strong solvents that break down the oil in the crankcase.. you should NEVER drive with that stuff in your engine because it essentially washes the oil away rather than letting it cling to friction parts like cylinder walls and it thins the oil you are running thru all your bearings and valvetrain.. i've always liked the ATF treatment a week before an oil change if i intend to clean the engine.

when I say the morning before, I mean that I put it in run it for a few minutes, then shut it off. Come back later and run it for a few minutes then sut it off and drain the oil. I usually only use it when I first buy a vehicle. After that I just do regular 3k mi oil changes with good oil.

I agree with the ATF treatment. I've done it over my past few oil changes, instead of the SeaFoam. I'm honestly concerned that the SeaFoam will cause too much gunk to come out, and either plug up the passages, or cause the seals to leak more....

wolfpackjeeper said:

when I say the morning before, I mean that I put it in run it for a few minutes, then shut it off. Come back later and run it for a few minutes then sut it off and drain the oil. I usually only use it when I first buy a vehicle. After that I just do regular 3k mi oil changes with good oil.

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gotcha.... but i know that alot of people DO drive with that crap in there.. good way to smoke ur bearings.

Doing this for years, 73 pick-up almost 300 thou.. Never hurt it..

ATF isn't a really hard core solvent, just thin and high detergent, so it shouldn't break stuff off, just wash it out. I'd be careful not to run it for long.

My favorite flush is to buy a spare, cheap oil filter, and a fill of the cheapest thin high detergent motor oil you can find, run the crap out of it for an hour or so, and then change it out hot. That's just about the same idea as using some ATF, but I think it works better if you run a complete extra change. Of course, nowadays, "cheap oil" is kind of an oxymoron.

XJ Stryker said:

Yeah it was my thread I got too much help so I will pass on this help to you lol

http://www.naxja.org/forum/showthread.php?t=951884&highlight=cleaning+the+rockers

I tired the diesel technique with lil results. Seafoam did work great for mine.

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Thanks for the link. I thought there might be a thread out there somewhere, (always is,) but I couldn't find it. So, the only thing I'm unclear on is how long to run the engine with the ATF or Diesel in it. Is it 30 minutes, a few hours or 100 miles?