Personally iv never done it. And I wouldn't suggest it either. Back in the day when motor oils where non detergent ATF had high levels of detergent and it was used to help clean engines.
Was it the best option then? Not really
Best option now? No chance
There are many good cleaners out there that cost just as much as ATF why not try those?
Its not a good idea . Modern atf only contains about 10% of the detergent potency of modern api sn motor oils. The atf would actually dilute new oil.
If we are talking about adding it to an oil burner that was low on oil, then why not it would refresh the additive package but could change the viscosity sincere most atfs are pretty low on that range.
That being said topping off with the correct oil is the better choice.
Like most urban legends, this one might have some basis in fact.
Way back in the day, some ATF formualtions contained whale oil, an ester.
Since esters are highly polar and the motor oils of the day had little detergency, these ATFs might have had a cleaning effect.
I wouldn't use ATF with any modern oil and anticipate that it'll do anything positive.
Having said that, you can find a few posts on the site in which members swear that they've used ATF as a cleaner with good results.
I have heard of this aswell, but like said above there are allot more detergents in modern oils so it does not seam to necessary. I used to hear "old school" mechanics talk about this.
It seams to me kerosene would work better (if you must !), I used to hear about this allot also. I have seen it done and it was scary the amount of [censored] that came out of early 70's 440 RV motor !
On an episode of Car Chasers they put some ATF in with the oil claiming it will reduce
sludge. Has anyone heard of it and have you tried it? Thanks
I've used ATF in the oil before. It didn't reduce the amount of sludge. It just reduced the amount of ATF I had in my stash.
You can try it if you're dying to find out the truth, but as everyone else has mentioned, don't bother.
Lubrizol is one of the major manufacturers of additives to lubricant blenders (along with Chevron Oronite, Infineum (ExxonMobil & Royal Dutch Shell), Afton, few others). Here is the list of ingredients in the additive package they sell to ATF makers:
Dispersants... Sludge & varnish control
Antioxidants... Prohibit oxidation
Antiwear... Planetary gear, bushing, thrust washer protection
Friction modifier... Modify clutch plate and band friction
Corrosion inhibitor... Prevent corrosion and rust
Seal swell agent... Prevent loss of fluid via seals
Viscosity Improver... Reduce rate of change of viscosity
Pour Point Depressant... Improve low temperature fluidity
Foam inhibitor... Foam control
Red dye... Identification
Yes, in my opinion it will clean up an engine. I had a ford with inline 6 cyl that had a couple of hyd lifters that were sticking and hammering away. Had a friend and also a mechanic tell me to add some atf to the oil, so I did and those lifters got quiet and worked fine for about a year. Eventually they started getting sticky again so I pulled the cyl head and replaced them.