ATF Engine "Flush" at Oil Changes

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TC

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I came across this today. Since the old-school habit of adding a quart of ATF to engine oil just prior to oil changes keeps coming up on this board (and elsewhere), I thought this interesting. It would seem that other products have significantly better solvent qualities for such purposes, be they high-tech (Auto RX), or low tech such as kerosene (Valvoline/Pyroil Engine Flush) or diesel fuel (Gunk/Solder Seal Engine Flush).

"MYTH: Adding a quart of ATF the day before an oil change will clean your engine. ATF added to the motor oil will clean the engine due to the high levels of detergent in ATF."
"FACT: ATF does not contain detergent chemistry. ATF does contain dispersants, which have properties similar to detergents. But ATF is not formulated to withstand the combustion environment inside the engine." http://www.quakerstate.com/pages/carcare/whattoknow.asp

For the record...
Detergent: "...an additive -- usually metal-organic chemicals...that helps keep oil-insoluble materials in colloidal suspension...A detergent is normally used in conjunction with a dispersant."
Dispersant: "...an additive, usually organic polymer containing nitrogen groups, that help keep deposit precursors finely dispersed in the oil so that they cannot form oil insoluble materials that can settle out of the oil. Dispersants are usually used in conjunction with detergents."
http://www.dcpetroleum.com/definitions.html

And before it comes up, I'm not suggesting that everyone use flushes of ANY type unless they're actually needed. Sneek a peek through the oil filler cap before deciding same -- oil firms agree that the best flush for a clean engine is no flush at all, just change the oil.

[ February 10, 2004, 08:29 PM: Message edited by: TC ]
 
quote:
Originally posted by cryptokid:
aye, i have read that. its a good read but doesnt really apply to ring packs.
Click to expand...
Why wouldn't it? What causes rings to stick, other than a mechanical failure?
I would think that atf would help.
 
quote:
Originally posted by TECH:

quote:
Originally posted by cryptokid:
aye, i have read that. its a good read but doesnt really apply to ring packs.
Click to expand...
Why wouldn't it? What causes rings to stick, other than a mechanical failure?
I would think that atf would help.
Click to expand...
Hi Tech:

I don't know about passenger car motors, but in HD diesel motors, the rings will stick/break if a poor quality oil is used.

A few years ago the EPA, to reduce blowby and particulate emissions, mandated a redesign of HD engines. The Ring Land was moved MUCH closer to the Crown Land, in some cases the distance was less than half of what it used to be.

This moved the Ring Land in to much higher temps, and the poorer quality oils quickly broke down and left heavy deposits in the Ring Land: this is called Grove Fill, especially Top Grove Fill.

Once the deposits become excessive, the ring sticks. With continued use, you get blowby and the other ring groves fill with deposits. Then all the rings stick.

With continued use, you can and should expect rings to break in this environment.

HDEO's with CG-4 and CH-4 ratings were formulated to deal with this problem, as the maximum fill allowed in the test is around 14%.

The problem returned a couple of years ago when the EPA mandated EGR in HD diesel motors, which as you can imagine placed SEVERE soot loads inside the motor. This also lead to ring stick/breakage. Thus, the CI-4 specification.

I'm sure a very good flush would help a lot, and I have heard very good reports about Auto RX. You want a product to not only knock the crud loose, but also to dissolve the gunk into smaller particles and to hold it in suspension.

I don't think ATF will do all that, so you had the problem with the plugged oil pickup.

BTW: plugged oil pumps and oil pickup tubes are common on HD diesel motors if they are neglected then suddenly you change the filters and oil to a high quality synthetic. The excess deposits overwhealm the additive package and everything turns to sludge.

I find it shocking that somebody would neglect such an expensive car. What's the old saying?

"Penny wise and dollar foolish."

Jerry
 
ATF has no sludge cleaning power at all. First why would ATF have anything in it to handle sludge? Transmissions do not see the heat and blowby that an engine sees. ATF is simply hydralic fluid with very weak additive package! A quart of naptha would have 1000 times the solvency of a quart of ATF!

If you want to sludge up a motor fill it up with ATF and drive around! Do not do this thoug if you actualy want to keep the motor in one piece!
 
i was not refering to adding a quart of atf to the oil, but rather filling the combustion chambers with straight atf, on an engine that has stuck rings. in my own expierence this has unstuck a stuck ring i had an in engine that sat for a few years. this engine when started and ran would constantly smoke oil out the exhaust. filling the chambers with atf and letting it sit 3 days, then draining them and running the engine stopped the smoking completly, and the compression increased.

so i am wondering why can atf do this, there must be somthing else in it besides detergent that can do this i guess?
 
quote:
Originally posted by cryptokid:
so i am wondering why can atf do this, there must be somthing else in it besides detergent that can do this i guess?
Click to expand...
Perhaps a wide variety of other oils would have done the same thing?
 
unlikely.
this engine sat pickled in motor oil while it was in storage, with its intake and exhaust closed off.
just guessing from how long it was in storage, it must of been api sh motor oil.
 
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