Anyone else done this?

[93TwotoneXLT]

I have a few mechanic friends who use ATF in their crankcase when they change the oil in their vehicles. They say that it keeps the engine/oil passages clean because of the detergents in the ATF. They only use 1/2 quart of ATF when they change their oil. I am thinking of doing this and was just wandering if anyone here had any experience with this, good or bad. They say they have been doing it in all of their vehicles for years and have had no problems at all. One of them had the valve cover off of his 3.0L Taurus engine(vulcan) to replace the VC gasket(120K) and his valvetrain looked IMMACULATE, like brand new, not even a slight "yellowing stain" on the rockers, springs,etc. Anyway he looked over at me, knowing that I am ever the skeptic with things like this, and said "see what I mean?" I am really close to doing this and would like to get some more input. Thanks in advance for all replies.

 

[Brandons]

I did it, several times, with no problems, just dont add alot if your worried about it. I cant see it doing any harm, but others may disagree. I also know a mechanic that does this and its particularily good on older engines to clean them out.

 

[msmith65]

ATF is rich in detergents -- it has to be, to keep the tiny passages in auto transmissions clean.

I've poured it straight down a carburetor to clear carbon out of a dirty engine while it's running. It makes a lot of white smoke. I can't testify to its effectiveness, though, because I didn't break the engine down before and after to compare. (Who would? )

I can't imagine it would harm what's in the crankcase. However, I doubt it has the lubricative qualities of engine oil, so I wouldn't run it more than a couple minutes, at idle, to clean the engine, then drain it with the old oil.

 

[93TwotoneXLT]

These guys are running 1/2 quart of ATF in their crankcase for 3,000 miles. Anyone think it would be detramental to the engine to run that amount for that long? I know that ATF is rich in detergents so it makes sense in theory to run a small amount in the crankcase to keep the engine clean, but I personally have no experience with this.

 

[Brandons]

Im not sure, i doubt it, since you already have engine oil in there then adding 1/2 quart. To play it safe id do what msmith reccomends just to play it safe, i do the same.

And btw what colors are you explorer?

 

[93TwotoneXLT]

Brandons, charcoal grey on top and navy blue on the bottom. Yeah, I am thinking of maybe using msmith's method as well. The mechanic with the Taurus has been using the 1/2 quart method for over 100K with no probs and a pristine looking valve train. But I do not know enough about it yet to do that.

 

[uh60james]

I wouldn't leave it in there for the full 3000 miles or whatever your oil change interval is but I I definitelly think it is safe to run it for more than several minutes. Should be fine running it the entire day you plan on doing your oil change without any problems. If your really worried about the sludge you should do this and switch to a high quality synthetic and also reasearch oils and stay away from those that have a high parafin content.

 

[Creager]

I used ATF to clean my cylinder walls before i put my new rings/pistons in

Ive also heard of people putting a pint of motor oil in manual trannys that take ATF to give more lubing properties to the ATF.

 

[msmith65]

An engine can be too clean. I once destroyed a camshaft when gasoline leaked into my oil over a long period.

Really, friends, messing with the oil formula is risky. All oil companies put detergent in motor oil, and it's a safe bet they put just enough in there to clean the engine without destroying the oil's lubricative properties.

Provided you change it regularly, that's all you need.

 

[cfkane]

BG products sells a Motor Oil Additive that is compatable with all oils and has detergents and anti oxidation components. Give it a try as it will clean your engine with little risk of damage.

 

[msmith65]

BG products sells a Motor Oil Additive that is compatable with all oils and has detergents and anti oxidation components. Give it a try as it will clean your engine with little risk of damage.

Perhaps you could supply some information -- aside from the company's own marketing claims -- to support those assertions?

 

[Bwana Bob]

Wouldn't the friction modifiers in ATF cause a problem?

You can add Marvel Mystery Oil to the crankcase, and some people swear by the Lucas oil additive.

Bob

 

[MarksSC94]

Hi, I am not concerned about the lubricative properties of the Tranny fluid. It is pretty slick as far as thin fluids go. I am concerned that since your motor oil is also part of a bearing, (called a fluid bearing), the viscosity will be changed quite a bit. The thickness of the fluid helps keep that very small distance between your main bearing and crank journal. Something to remember, that all though we place these "bearings" in for main and connecting rod bearings, the oil is the real bearing so there is little metal to metal contact. You can think of the metal "bearing" that we put in for mains and the journal of the crank as the races of the brearing and the oil is the roller part of the bearing. This is what makes it a fluid bearing. Most of the metal to metal contact that is made while the engine is running on the mains is when the engine is first started. Some of the tools I have worked on in the biz I am in use air as a bearing. It has a lot less drag and is renewable so we don't have to have a container full of it. On one tool we use a magnetic bearing. It has a fan that has blades made of Titanium and it spin upwards of 60,000 rpm as a normal operating speed. Those are really slick and need to operate in what everyone else would call a vacuum, but still has a few molecules of air in it. Too many molecules of air those nice titanium blades thinner than paper turn to speggetti. :roll:

 

[93TwotoneXLT]

I went ahead and put exactly 1/2 quart of tranny fluid(mercon V) in my crankcase when I changed my oil two days ago. I am changing the oil later today(it's 3:00am right now) with 5w-30 semi-syn(motorcraft). So, I ran the engine for two days, maybe 50 miles total, with the tranny fluid in there. I decided to do this because my mechanic friends have both been doing it for years with no ill effects whatsoever in their vehicles. I am not doing this with my Ex, because that truck has had religious oil changes for its lifespan and has 120K on it, so it has been driven enough to keep everything clean and free flowing. I am actually doing this on a 95 Olds 88 that I bought from my fiance's mom with only 23K on it. The car is from florida and sat for about 4 years only being started once a month. She said that she would let the car run for about 15 minutes. I decided to do it because I thought that since the car sat for so long, it may actually need a little engine flush, so I went with the mild 1/2 quart method. Thought I would give you guys and gals an idea of the method of my madness. I can see though how putting more than a quart of tranny fluid in there for any extended period of time could actually harm the engine. As a person said earlier, an engine can be too clean and not get enough oil to lubricate moving parts properly.