doh! transmission fluid in engine. - PeachParts Mercedes-Benz Forum

angst · #1 07-23-2007, 10:54 PM

I just finished changing my trans fluid and filter and replacing the k-1 spring.
Things went very unusual. By unusual I mean that no stripped or snapped bolts or the usual dramas that turn a 3 hour job into a mission.
Every thing buttoned up nicely and it comes time to top the fluid up. I proceed to open the engine oil cap and start pouring in transmission fluid in.
I put somewhere around 10oz in the engine before my brain turned back on and snapped out of the euphoria of a job well done almost being complete and I smacked the funnel out of there.
So. Im probably not the first person to do somethin so stuupid so don't ridicule me.
Ive been 2700 mi since last oil change. Can I let this ride? 200mi of driving planned tomorrow morn. Do I need to set the alarm real early and change the engine oil or will I be ok?

JimmyL · #2 07-23-2007, 11:00 PM

Great forum name! Great avatar!
There are not enough folks who appreciate angst.

I'll let smarter folks answer your question as I don't fully know the ramifications of 10oz of tranny fluid in the oil. That may be like a pint of Marvel Mystery Oil, but it may be too solvent-like.

#3 07-23-2007, 11:02 PM

I doubt that small an amount for such a fairly short distance will do any harm. I've seen people intentionally put far worse things in their oil.

cyman73 · #4 07-23-2007, 11:15 PM

Unfortunately I had the same brain fart happen with my Ford Windstar.

I am not sure, but I really think the gaskets were affected by the ATF fluid in my engine.

I was changing the oil when I accidentaly poured about 1/2 quart of Synthetic Mobil ATF. I had already poured 4 quarts of Mobil 1 into the engine

. I didn't think it was a truly bad thing so I decided not to waste the oil. Well, after about 4K miles and two oil changes later, all of my seals failed. The valve cover seals and oil pan seals started leaking. Fortunately these gaskets were still covered by the Ford extended warranty along with a new transmission that the dealer changed. I am not claiming that the transmission had anything to do with the ATF being poured into the engine, after all Fords are known for poor automatic transmissions. I am very suspicious of the gaskets failing with only about 60K miles.

I would change the oil ASAP. Just my $0.02.

TheDon · #5 07-23-2007, 11:17 PM

ooops...

Jeremy5848 · #6 07-24-2007, 12:46 AM

...and to drive the lesson into your head real good, yes, I think you should change the engine oil. Just don't pour the used oil into the transmission.

rs899 · #7 07-24-2007, 11:51 AM

Sooo ....Angst. What did you do...or not do?

If it was me, I would not have changed it. IMO ATF is so close to motor oil (even more highly refined) that it would not make that much of a difference to the bearings (transmissions have bearings, too) and seals ( transmissions have seals , too).

Rick

shingleback · #8 07-24-2007, 03:03 PM

I would drive it for a little while. An old mechanic's trick is to pour about 1/2 L of ATF into the crankcase and drive for about 500 miles to clean out the oil passages. This also quietens noisy lifters, if they are hydraulic. I have used this trick on quite a few cars, with no detrimental effects.

WINGAS · #9 07-24-2007, 03:21 PM

Ditto shingleback. Its a good cleaner for a short period. Dont have the shear properties you need for bearings/lifters-follwoes. Aint no clutches in a crankcase!

But you might have actually done the engine a favor. Change it out ASAP though.

SirNik84 · #10 07-24-2007, 03:23 PM

yep.... not that it matters in your engine because you don't have hydraulic valves, but I've poured ATF into older American V8 engines... and it does take away clacking in the valve train from sticky lifters.

F18 · #11 07-24-2007, 03:47 PM

I agree with shingleback and WINGAS! I had a diesel mechanic years ago tell me to add some ATF to the crankcase and fuel tank now and then.......He said the higher detergent in the ATF would benefit the engine and injection system.

ConnClark · #12 07-24-2007, 05:35 PM

For all practical purposes, ATF is Marvel Mystery Oil. I would drain the oil to the proper level then drive the car 5 miles and finally change the oil and filter. Drain your oil cooler too.

kerry · #13 07-24-2007, 05:44 PM

Just to be on the safe side, add a little TransX and drive it for a while before draining. Should resolve any future problems with the gaskets.

crashone · #14 07-24-2007, 09:41 PM

Since you have 300 miles to go before your next oil change---drive it like you stole it!!

That small of an amount of ATF will not hurt but will help as stated before. I too have been told to do the ATF treatment in the crankcase and fuel tank to help clean out the gunk. I would not reccomend 7 qts ATF to 10oz oil tho.