I've heard of people adding a quart of ATF to their engine oil for about 500 miles or so before changing it out to clean the gunk out of the motor. My oil gets pretty dark by the time I change it so I'm guessing there a little bit of sludge and what not in there. I'm using Mobil One 10W-30 and it goes from the amber color it originally is to darkish brown. Not too bad I think but still too dark for comfort. My motor's got 126k miles on it but it still runs very strong and hardly consumes any oil, no strange noises at any time either. I never have to add any oil between changes. Would it be safe to use the ATF trick or would I run the risk of causing other damage. Furthermore, I just checked the oil and saw what seem to be metal particles on the dipstick. They also could be tiny bubbles because even though they were visible on the dipstick, they wouldn't shine in the sun no matter from which angle I looked at them and I couldn't see them after smearing the oil on my finger either. Might just be my paranoid imagination playing tricks on me but I want to make sure I don't mess something up.

 

Anyone?

 

I have heard of some engine builders using nothing but ATF for the first 500 miles on a engine because it is a really good lube and is supposed to be comparable to 10W-30. I'm not 100% sure tho.

 

It cleans, but it could potentially cause a problem. As old stuff (varnish, sludge) is broken up in the engine, some of it may clog an oil passage or two. Then you end up starving a part from oil until it seizes up. I wouldn't do it.

 

After reading some horror stories I personally will not flush my motor. If you do have a lot of sludge in there, if you break it up where will it go? Could get on the oil pickup and stop something up. You should have seen the sludge build up in my brothers motor when we pulled it for a rebuild, there was so much sludge on it you could not see any metal on the inside of the block or top of the head!! I'm sure if you have any sludge it is no where near that bad, but he wasn't having any problems with his oiling system, the motor was just worn out.

 

If your motor is running good as you mentioned, I wouldn't do it. Like the others said you could open up a can of worms.

 

I guess I'll just go with a couple of earlier than usual oil changes instead. Thanks guys .

 

I did it to a 95 t-bird that was not serviced regulary had to change oil pump and pick up screen be cause it was plugged! I ran 4 atf and only 1 oil for 500 miles than keep changing 500-1000 miles adding i more oil motor was clean ran for 75,000 more miles than sold it still running! but this was an extreame case and I paid $200 for the car so I had nothing to lose! Your oil is getting dirty because it is doing its job i wouln't change a thing with your maintenance!

 

ATF does not contain any more detergents than regular oil does. It's an old wive's tale, based on the fact that many years ago it did, but not anymore.

Most ATF is simply a thin oil similar in properties to a 5w20 motor oil.

I've seen an oil analysis on ATF and it's true, the detergent levels are no higher than motor oil.

Your best bet for cleaning your motor is a product called Auto-rx. I've used it and believe me it works. It cleans slowly though, it's not something you put in and run for 10min. It's something you put in and run for 500 to 1500 miles. Because it cleans slowly, and dissolves the sludge into liquid, it is safe for your engine since it won't clog up the system.

 

I understand that you are the "oil" guy, or whatever. But it is hard for me to believe that ATF has no more detergent properties than reg engine oil. Show us please

 

When you look at the job a tranny does as compared to an engine, which one is more likely to get dirty, the one transmiting power or the one burning petrolium products? Never heard of carbon buildup in a tranny unless it was destroyed by overheating and then the fluid is useless anyway. When you look at it like that it makes a whole lot more sense doesn't it?

 

Ditto on the auto-rx. I used it on my Jeep at 136k, and it even cleaned off some of the stains on the dipstick. My Jeep was poorly maintained and also needed a new oil pump and thorough cleaning of the oil pan. It was bad enough that it lost oil pressure when warmed up at times. I ran some Gunk motor flush, and it fixed the oil pressure loss for about 2.5 months, until it came back as bad as ever. Then it was time to drop the pan and do some cleaning.

Those flushes do work somewhat (if you drop the pan afterward to clean it out), but auto-rx is alot safer and actually swells and reconditions old seals.

Jason

 

ATF does hoave some cleaning properties. It will get grease oil off your hands but I wouldn't recommend this as an alternative to hand cleaner. My engine builder uses this to clean cylinder walls after honing.

When I've had to clean out the engine in a flood car i drain the oil, remove the spark plugs and PCV valve then fill the engine to the valve cover with kerosene and let it soak. This cleans so well that its like the engine was assembled without a single drop of oil. Thats why I'll never do it to my own car. Insurance companies like the cheap way out.

 

Do a carbon clean on the engine to flush the crap out. This was recommended to me by my mechanic and I've done it on a couple of other beater cars I've owned. Improved performance dramatically and oil changes seemed to come out a lot cleaner after. Can't remember what the stuff was called, but I'm sure u can find something in your area if you ask around.

 

Do you mean Seafoam?