Since I have been doing my own oil changes in my cars for over 20 years, my well trained mechanic told me to add 1/2 pint of ATF to my oil changes in both my diesel (230K)and gasser (120k).

This is in my mind and will not leave until I can understand it. Has anybody heard of this before. Is it somthing done with the old not so good oils of the old days? May be to keep the top end lubed?

In the oil???

I would not. ATF is a lighter oil and does not provide the lubrication you need. It may actually clean some sludge in the oil system, But I would rather see you put in Synthetic oil, it will do the same thing. When I was 16 and worked at a gas station in New York the mechanic ther used to use ATF to clean his hands after work. If worked better thatn anything available at that time. If my hands are really bad, I'll do the same thing and use GoJo to take off the ATF.

In the fuel tank??

This use to be an old wives tail that has been passed down for quite some time now. Used to heer it back in 80 when I got my 220D. Mercedes did a test of the ATF in the diesel fuel idea. They found it actually caused the injectors to clog more than it helped. After the test Mercedes advised not to put ATF in the tank.

Mercedes does recommend Chevron Tectron as an additive to clean injectors. Techron and an Algea treatment are the nly additive Mercedes recommends.

Dave

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1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

Old wives tale!!!

Use a API service category SL oil in a viscosity range recommended in the owners manual for the expected ambient temperarture range until the next oil change.

If the engine is supected of having a "sticky lifter" as evidenced by a ticking noise in the valvetrain use a HD diesel engine oil - API service category CI-4. These oils have a richer detergent, dispersant, anti-wear, and anti-corrosion additive package, however, since the combustion byproducts of some of these additives can degrade catalysts, they are not recommended for continuous use for catalyst equipped cars.

For more info on motor and gear oils visit www.api.org

Duke

DON'T do it skydive. I also knew an older Gentleman with a '66 Riviera that swore by running ONLY ATF fluid right before an oil change. He ran it for a couple hundred miles with the ATF in it, and claimed it cleaned the engine beautifully. While this is certainly more extreme than a 1/2 pint, ATF oil is a completely different formulation than the oil used for a crankcase. Although it is high in detergent, it is not meant to provide the same protection under extreme dynamic rotating loads. The last time I saw him his Riv was nowhere in sight. He told me he had spun every connecting rod bearing in the motor, and probably the mains too. The ATF oil certainly cleaned away all his bearing material! Use the synthetic as dmorrison suggests.

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1995 S600, 1 of 618 (sold)

"Speed is just a question of money...how fast you wanna go?"

LONG LIVE THE W140!
Visit my Web Page at www.v12uberalles.com

I have never actually heard of anyone driving around with ATF in the engine oil for a longer period.
But it is well known that it can be a problem solver if you've got sticky lifters or sticky piston rings. (high oil consumption)
But that procedure does not include driving the car!

Freestyler

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Never criticize someone until you've walked a mile in his shoes. That way, when you do, you're a mile away -and you have his shoes!


'86 300E optically converted to '95 E300 (Sold)
-Blauschwarz on silver
-Black leather
-17" AMG & 15" AMG for winter

What exactly is so wrong with motor oil that folks want to mess around with additives and alternatives? These motors will generally run long enough to wear the rest of the car out if properly maintained. Overheating and poor maintenance are what kill motors prematurely, not bad oil formulations.

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1986 300E 5-Speed 240k mi.

Thank you all for the very good information. I can now go on with my life.