Thread: Running Trans oil as engine oil

So one of my friends was telling me that one of his friends ran his engine completely with just trans fluid. meaning he would fill up his engine with trans fluid, not oil. He said that you can do this but you have to start doing it on a brand new engine that has never seen oil before.

So whats up with this.

Originally Posted by 04CompG

So one of my friends was telling me that one of his friends ran his engine completely with just trans fluid. meaning he would fill up his engine with trans fluid, not oil. He said that you can do this but you have to start doing it on a brand new engine that has never seen oil before.

So whats up with this.

I wouldn't try it if I were you. Bad things would happen. Engine oil is for engines. Transmission fluid is for transmissions. They are made completely different for the different applications and different environments. Trans fluid will not hold up under the pressures of an engine.

Agreed. Trans fluid is generally thinner than motor oil, does not have the extreme pressure additive motor oil has and nor does tranny fluid have the additive package to keep contamination in suspension or to combat combustion process by-products.

I've heard of it being done for 50 miles prior to an oil change under the assumption it will clean the engine out (an assumption I'm not sold on). Never heard of it being done all the time.

I promise you transmission fluid has NO WHERE near the cleaning properties that motor oil does. I dont know how that ever got started but transmission fluid has virtually nothing in the way of cleaning abilities.

Now what I could 'possibly' conceive it doing, since its a thin oil, on the thin side of a 20 weight motor oil, is maybe allowing the engine to run warmer and maybe burn some stuff out but thats a stretch at best.

You want serious engine cleaning ability, pick up a bottle of Auto-RX. By far, bar none THE best engine cleaner man has ever known.

syntheticshield your telling me that Amsoil doesnt have the best engine cleaner???

Originally Posted by 04CompG

syntheticshield your telling me that Amsoil doesnt have the best engine cleaner???

As much as I hate to say it, 'tis true. Now Amsoil's Engine Flush is a good product and one of only a handful of such products that doesnt contain Kerosene, but its not really targeted to do the work that Auto RX does. Look at it like this.

You go to the bathroom and wash your hands (hopefully) after all is done. Thats Amsoils Engine Flush. A surgeon litterally scrubs his hands before surgery. Thats Auto RX.

Isn't transmission fluid just modified hydraulic oil? I've heard of using 30w engine oil in a hydraulic pump, but never the other way 'round. Though you can run a little kerosene in your engine to clean it out some...

Actually, automatic tranny fluid is a lubrication oil designed to be used as a hydraulic fluid. It lubricates, provides pressure, and cools the tranny.

Correct, that is why you find some makers specify Automatic transmission fluid in their power steering systems.

Originally Posted by SyntheticShield

Correct, that is why you find some makers specify Automatic transmission fluid in their power steering systems.

I have used tranny fluid as PS fluid before. No issues there.

Yeah, there are some applications that call for it, GM unfortunately, specifically the GP isnt one of them, though Ive been tempted to try it out.

Originally Posted by Zef_66

I have used tranny fluid as PS fluid before. No issues there.

Yea, it is an "old school" sort of "trick" that ATF has a lot more detergent to help clean out systems, like the power steering. I would not condone it, honestly, as you are better off just flushing the system and installing a filter if there is that big of a concern. How it turned into the oiling system as the OP suggests baffles me a bit, though.

Tranny fluid is good for fuel injector cleaner if added to gas tank

Sorry, it wont work as a fuel injector cleaner either. Its cleaning abilities are limited at best and used in fuel it would only become less so. It will, however, serve as a lubricant for the pump. In fact it is used frequently for that purpose in home made octane boosters.

Ford uses ATF as PS fluid a lot. Seen a lot of Cougars like that.

Right, Ford is one of them that uses ATF in their PS systems. I sure wish others like GM would catch on.

ive used stabil fuel as an injector cleaner, seems to work good

Originally Posted by Street Wolf

Heard of it, seen it done, thought it was a stupid idea, researched it, found that it was indeed a dumb ass idea rather than just a stupid idea.

lol hell yeah