Adding Tranny Fluid in Before Oil change to clean?

Status
Not open for further replies.
Joined
Nov 16, 2017
Messages
71
Location
Georgia
Just thought about something reading another thread. I use to put about a 1/2 quart, (sometimes more sometimes less) of regular Transmission fluid in my car (02 Lincoln LS below in Sig) a few days before I did a Oil and Filter change. My Dad use to do it all the time. Said it helped clean the motor internals some.

I put it in a day or 2 before and in essence drove the car for a day or 2, or 3, ( 50-2000 miles?), sometimes a little more right before I changed and drained the oil and filter.

I've Googled this a few times. Not lately tho, and read Yes, No, oils are much better at cleaning now a days, could loosen something hard sludge and damage and so on? I'll admit I still do it every 2 or 3 oil changes if my eyes light up and I see a quart of cheap Tranny fluid on sale. Never concerned about the type, but never Sys Fluid due to cost per quart. Only requirement is that its Red. LOL! About some thoughts/input. Anyone else do this?
 
It's an old timer thing to do. Save your money and the environment. Lots of people on here with cars that last 200-300k or more and they don't do that. They just change the oil on a regular basis. This might have meant something to cars in the 60's, 70's or maybe 80's, but not to today's modern engines and oils.
 
Nothing better than Mystery Marvel Oil for a crankcase flush. Forget the tranny fluid and add some MMO and you'll be good.
 
If you really want to do a flush, there are some good inexpensive flush formulas that will work better than ATF. Napa has Liqui-Moly motor flush
smile.gif


Otherwise, you're better off just changing the oil more frequently
 
Originally Posted By: Matagonka
Nothing better than Mystery Marvel Oil for a crankcase flush. Forget the tranny fluid and add some MMO and you'll be good.
Yes MMO is the way to go. And most importantly - IT'S RED! But seriously, little MMO (1/4 of the bottle) in the crankcase few days before the oil change will cause no harm, and will clean up any build-up of varnish/sludge.
 
Originally Posted By: zrxkawboy
Old mechanics' tale. ATF actually contains very little detergent.



Agreed. Transmission fluid doesn't need to fight with combustion byproducts so it doesn't need loads of cleaning agents. What a silly additive to add to engine oil in hopes of it CLEANING.


crackmeup2.gif
 
Originally Posted By: Vlad_the_Russian
Originally Posted By: Matagonka
Nothing better than Mystery Marvel Oil for a crankcase flush. Forget the tranny fluid and add some MMO and you'll be good.
Yes MMO is the way to go. And most importantly - IT'S RED! But seriously, little MMO (1/4 of the bottle) in the crankcase few days before the oil change will cause no harm, and will clean up any build-up of varnish/sludge.


I'm going to try this on my Rav4. It's been consuming more oil than usual. I don't think it will hurt anything.
 
That was a trick back in the day when tranny fluid contained whale oil... It was a great cleanser.

That went away in the late 1950's... Has not been a useful process ever since
frown.gif


MMO is still good to add 1 qt for the last 100 miles or so, before your change. It cleans gently and helps get all the gunk out
smile.gif
 
Originally Posted By: BrocLuno
MMO is still good to add 1 qt for the last 100 miles or so, before your change. It cleans gently and helps get all the gunk out
smile.gif



What if the oil level is on the full line and you add a quart to it? Seems like overfilling it by a qt.
 
Originally Posted By: SatinSilver

What if the oil level is on the full line and you add a quart to it? Seems like overfilling it by a qt.

Yes it gets over filled, but only for 100 miles, and plus MMO usually burns up before 100 mile mark. I did such over filling before on 6 different cars. Nor harm was done, no leaks were started, but engines were a bit cleaner. And, according to their drivers, cars ran better in general after the MMO treatment.

My personal experience is in 2006 Pontiac Vibe AWD that was consuming 1qt per 100 miles and had blue smoke out the exhaust in the morning or cold start. Lots of blue smoke. After first MMO my consumption was reduced to 1qt per 3k miles, blue smoke was eliminated. After a couple more MMO treatments consumption was nearly zero per 5k miles.
 
Walmart full synthetic oil cleaned out my gm 305 crate motor that had 16 years of abuse from my dad.

It also smokes for 5 minutes if I let it sit for a month too.
 
If you want to add something there are far more useful things than transmission fluid. MMO, a qt of kerosene, seafoam, bg109 ( now called EPR), Kreen, berrymans B12 chemtool. Gunk makes an engine flush that you can pick up at Walmart. I’ve used it and it appeared to work.
 
I've had two cars that had over 175,000 miles on them when they were retired. I never used anything like that in engines. If you use a good quality oil and change it at reasonable intervals, there is no need for that stuff.
 
Originally Posted By: KL31
We need a myth busters sticky somewhere for questions like this.


Good Idea!

Check the myth section before posting your question!
 
Last edited:
Status
Not open for further replies.
Back
Top