i've recently heard from several people that substituting a qt of transmission fluid for a qt of motor oil is a great way to internaly clean the engine between oil changes, anyone ever tried this?

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Anyone can design something but it takes a genius to make it simple.

I would not risk adding ATF or any other snake oil, cleaner, elixir to my oil. Just my opinion and I'm sure there are others who will differ. My test is "what's the worst that can happen and can I live with it"? Irreversible engine damage is the worst that can happen and it may go undetected for a while.

My advice is to change it hot, completely, often and know if you are driving in "harsh" conditions. City driving is harsh. I change mine out every 3000-5000. The top end, to include cylinder walls, still look great at 161,000 miles.

A high quality oil, not necessarily synthetic, with a quality filter is the way to go. The oil (synthetic and dino) you buy has enough additives to take care of business to include "cleaning". A good read is http://www.bobistheoilguy.com/

Is there a specific issue that you are trying to address?

I clean the outside of the engine, not the inside. Contemporary motor oils have cleaners installed. Regular changes, with filter will suffice.

Check engine vacuum, check compression, if it runs down the road, 70 mph, gets the groceries, what more could a Brickhead want? God bless the Bricks.

Greetings:
We had a 1986 hi mileage German made Jetta. Very sturdy suspension.We changed the Valvoline dino oil at home fairly often. I tried the 5 quarts of Valvoline semi-synthetic and new Fram filter.50 miles later the oil light came on. Added oil, changed sender, etc. No joy. Finally got worried and towed it to independent German shop (Karl Merkel in Indy). New Oil and filter change and everything was fine again. They said semi-synthetic oil completely and quickly cleaned engine and totally clogged the 50 mile old Fram filter. They explained cleansing was a typical effect of converting to synthetic and semi-synthetic oil. It cleaned and yet it was still motor oil with lubrication properties that ATF would certainly lack. I would consider some form of quart of synthetic oil and 4? of regular oil, or a special oil flush, which usually is used at idle for an hour or so.

John in Avon / Indy

More than anything else I think you've pointed to a problem with Fram filters. Although I work for the parent company, I will state unequivocally that these are "minimal" filters which do not compare well with OEM filters.

I had a '91 Jetta which routinely sounded the high-pressure oil pressure failure buzzer when I used Fram filters. The OEM VW filters by Mann worked fine!
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In God We Trust. Everyone else, keep your hands where I can see them.

Fram, the orange kiss of death.

Seriously, these engine purges spell trouble for oil passages. A sudden loosening of 20-year accumulation of crud circulating through the closed oil circuit is asking for trouble, despite the many anecdotes offered. Slow and easy wins the day. Mix a little syn oil or Techron fuel system cleaner, routinely, prior to oil changes.

Chris in Vt, 1994 945 153K.

Add some Techron in the oil? Interesting idea, but isn't that doing essentially the same thing as adding Marvel Mystery Oil or Auto RX? You are adding a chemical with some solvent property.

I mistakenly suggested Techron in the crankcase, meant to say use the Techron in the fuel tank, for one tankful prior to oil change. MMO is another standby as a detergent in the crankcase. Why, I recall Don Foster moons ago suggesting kerosene in a recalcitrant automatic transmission.

Chris in VT, 1994 945, 153K

Are you trying to get fired from your job?

Just a thought!
jorrell
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92 245 287K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!

Shhhhhhhhh!!!!
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In God We Trust. Everyone else, keep your hands where I can see them.

Had a 78 Honda Civic countless years ago when dinosaurs still roamed the earth and one had to duck spears and not bullets, it was a massive oil burner despite only having 30K miles on the clock "it sat for five years before I got my hands on it". I did a compression check and found that all four itsy bitsy cylinders were down on pressure by 30 to 40 PSI from spec.

The solution was to remove the plugs, fill the cylinders with kerosene, then drain the oil and over fill the crank case with kerosene instead of oil. I let the engine sit in that condition for three days followed by cranking the engine over for an additional three days by hand "once a day" with a wrench. After draining the "crud" out of the crank case and spinning the engine over with the starter to clear the cylinders, I put oil and plugs back in it.

After that, the compression of all four itty bitty cylinders was perfect and the oil galley in the head was clean, heck, she ran great after that!

She finally died after a few years due to rust and a bent rear suspension, but thanks to the junk yard that bought her for $40, she became their "torch wagon", ie. holes cut in the roof so they could put welding gas cylinders in it so they could drive around the junk yard!

So yes, petroleum fuel products will clean an engine and help disintegrate carbon deposits but caution must be used. If you are asking why, clearing the cylinders will BLOW kerosene and kerosene vapor everywhere, one spark, it's all over!

jorrell


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92 245 284K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!

I was told to use tranny fluid to loosen up a sticky lifter in a OHV V8 with hydraulic lifters. It didn't work, by the way.....I used an engine flush solution on an old BMW that had been sitting for years and was running rough. It smoothed out a bit, but seemed to be a lot noisier than before I cleaned it.

Automatic transmission oils are formulated for transmissions which are hydraulic in nature, and ATF is a hydraulic fluid. A poor idea.
Change the oil frequently with a good grade of engine oil, and the results will be dramatic, AND safe for the engine.

Old wives tale. Don't do it.

There are some specialty products some people swear by for engine internals cleaning, particularly AutoRX which is a bit of a cult favorite on bobistheoilguy.com. I've never used it, but if I were trying to improve engine internal cleanliness AutoRX is the way I would go.

http://www.auto-rx.com/

Had a Rice Burner in the 70's that looked like maybe did burn rice at one time when you looked at the upper head. One day the choke on the Toyota stuck and I did not know a whole lot about carbs. Did have an old Chevy Truck used it to jumper the battery and kept trying to start it for a whole afternoon. A buddy who went to college with me found a clip stuck and the car fired right up. Drove the thing to work and back (about 30 miles) there in Dallas that night and the next day checked the oil level. The level was well above the line and then the smell of gas hit me. Jumped in the truck and went and got a new filter and oil. As the oil pan nut was removed the oil hit the catch pan with a rush. You should have seen the goo and stuff that came out of there and the speed it came out. After putting in the new oil and filter, that car had the cleanest oil you have ever seen months later. The head was as clean as you could get one without pulling it in fact.

To this day not sure what was a closer call, the Toy oil pan with extra gas or the epic Fuel Pressure Regulator failure on Inga that sent all that unburned gas out the tailpipe.

Not suggesting this to anyone, DO NOT TRY THIS AT HOME. Leave it to the Darwin Award winners, the good lord smiled that day . The Toy did not go out in a blaze of glory with me in it. The Point of all this is, that a good solvent (petroleum based) is most likely the best option for dissolving gunk. Would highly suggest something with a bit higher flash point however than gas.

Converted Inga over to full synthetic oil a couple of years ago and the oil was bright red almost the day it was put in the car. You can see the varnish on top of the head slowly going away, not to mention how easy to clean the throttle body and hoses now. The synthetic stuff does not turn to orange goo up by the large intake hose or in the Throttle body like the dino stuff does.

Start with a good synthetic oil and see what kind of results you get would be my vote. And the thing about your car may start leaking oil when you go to full synthetic is a bunch of bunk. Run one with a clogged flame trap, that is what a massive oil leak looks like! And yeah I did that, but trying to find what the heck a flametrap was turned up Cleanflametrap.com and all this neat Volvo stuff. A link on that site lead me here so it's all good now.

Regards,

Paul

If I had a known sludge issue in an engine I would definitely not use ATF to clean it out. Presuming a 4 qt. system, I would get 4qts. of cheap oil, pour in 3.5 qts and a 16 oz. can of Amsoil engine cleaner. Start the engine with a new filter, run it for 15 to 20 minutes, drain the whole works out, change filter and oil, put in a pint of Marvel Mystery oil with the next batch of clean oil, and change out your oil filter every 1000 mi. for the next 3000 mi. When your oil starts looking decent, I'd go ahead and change over to synthetic, and be done with it. I run my fuel injected Volvos 20,000 mi. on the synthetic I use, and change out the filter every 5,000 mi. Because of the probability of gas contamination in my 122s, I cut that interval in half for the B 20s.

Sounds nuts to me. How do you know what tranny fluid will do under enginee heat and pressure, not found in the transmission. Could gum up your filter or oil pump or clog the rings and cause massive engine failure.
Better to add some reliable oil treatment and change the oil and filter than take that kind of a chance.

It's hard to get a B230 too sludgy. ATF worries me because of friction additives.

If it's sludge you're worried about, just run synthetic oil full time.... double the drain interval vs dino oil, and press on!

-Ryan
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Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars, GT Braces, Draco Wheels
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars

You can simply start substituting a quart of full synthetic in with your regular oil at oil change time and it will overtime, clean out a dirty engine. This way it is not a sudden break-up but done a little more slowly.
Charles

I have done the same thing...only different.

My family has bought cars that have been all sludged up. We have run the cars with 1 quart of Diesel fuel to 3 quarts of oil to break up the Sludge.

We have also taken a car that was sludged, ran it with the old oil in it until it reached temperature, dumped the oil and put in 4 quarts of Diesel and ran it for about ten minutes.... when we dumped that out, Whoa!!! Looking at the top of the head after that, Big difference from the gak that was caked on the Head.
Diesel fuel is a light lubricant that's why we prewarmed the engine and did not race it up ... but it cleaned well.
The thinking, much like Tom's was this Engine is Not happy like it is, we have nothing to lose by using a Very thin lubricant that will break up the crud. my brother drove that car for a few years after we did this and many other things to get it roadworthy.


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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

Yes I've done this to a B20 that I aquired that had quite a bit of sludge buildup on the valvetrain. But not in the ratio that you quoted. I was a pint low on the crankcase oil and topped it up with a pint of ATF for the last 500 miles before the next oil change. Did it twice and it did work to clean things up pretty well.

- HOWEVER - I would not use 1:1 as you suggest. I think that would be the death knell of the engine.

Regardless, I would only do it on an engine that already had a questionable amount of sludge that needed cleaning. And when I did it I was already resolved to the fact that I may have to rebuild it afterwards anyway. But didn't have to in the end.


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'60 PV544, '68 220, '70 145, '86 745T