'94 Ford Explorer. ATF in oil?

'94 Ford Explorer V6 4X4

I've asked mechs. about this and they all say it's not possible for ATF to leak into the engine, basically I must be an idiot who's not paying attention to what he's pouring and where. I agreed that it shouldn't be possible and assumed I made a mistake.

Since then I've changed my oil 6 times very carefully. Reading the labels and smelling the oil before pouring it in.

Also I have had to add ATF to the trans. about 1-2qt. per week.

When I drain the engine oil. there has been way too much and it's reddish and smells like ATF.

So don't bother telling me it's not possible and start looking outside the box and consider how it might be possible.

Let me repeat: THIS IS HAPPENING

How MIGHT it happen?

Thanks for anything you can think of.


it has been smoking like crazy.

I do know where to put the fluids. I've been driving this thing for 8 years and changing fluids myself. this has only been for the last 6 months. I have never seen a puddle underneath the vehicle yet the ATF is always lower than it was yesterday.

Also the transmission doesn't seem to have 2nd gear. but it's been like that for about 3 years and I'll buy something easier on gas before I spend $1000+ to replace it

Update 2:

this has only BEEN happening for 6 months, I've been changing the fluids the whole eight years.

8 Answers

  • Ron B
    Lv 6
    1 decade ago
    Favorite Answer

    There is only two ways ATF could possibly get inside an engine without being poured in there. One is through a vacuum hose attached to a leaking modulator valve, which I'm not sure that you even have. If that were the case the engine exhaust would SMOKE like hell and would have to empty the tranny to have a chance to make it past the piston rings and in to the crankcase. Second way would involve the occurance of two problems at once. First the transmission cooler would have to be leaking ATF into the coolant and then the coolant would have to be leaking into the crankcase taking the oil with it, but you say nothing about adding coolant. In any case I have never seen either of these remote possibilities happen. I bet the sentence that states "Also I have had to add ATF to the trans. about 1-2qt. per week." say it all. Or someone is messing around with you and pouring the ATF into your engine.

  • 1 decade ago

    I'm afraid this one is a bit of a stumper, but if you do that, you should check if your coolant lines are fine.

    One possibility that I can think of is that your transmission cooler, if it's built as a part of the regular radiator, may be leaking into the coolant, and that's how it's getting into the engine, but that doesn't explain how it's getting into the oil. Since coolant should never meet oil, much less end up in oil.

    I'll have to conclude that there's something not kosher with your engine's "plumbing", if you know what I mean. ;-)

    When's the last time you had your transmission 'serviced'?

  • 1 decade ago

    I'll play your silly game. So here goes.

    If, your transmission bell housing were hermeticaly sealed and could hold pressure without the transmission fluid pouring out of the bottom where the starter is mounted, AND the engine oil seals were damaged, AND the transmission were able to pressurize the the area that the flex plate, torque converter, and starter bendix is, AND that oil pressure was great enough to force the transmission fluid into the engine, then yes it could happen.

    However, that could NEVER happen.

    When you add transmission fluid, where are you putting it?

    In the SAME dipstick tube I hope with a funnel........and NOT the engine.


    Are you draining the transmission, and not the engine?

  • 4 years ago

    Assuming no one is messing with your vehicle, the vacuum hose from the modulator is the only normal way. Extremely improbable but did you inspect the cooler lines very closely? A cooler line rubbed through the oil pan is the only other possibility that comes to mind, unlikely to do what you describe with no external leaks, but worth a look. I've seen stranger things that would verge on the impossible yet were true. Like a piece of plastic cutting a steel line with no damage to the plastic, etc. Good luck!

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  • Anonymous
    1 decade ago

    If said vehicle has an oil cooler the handles both atf and engine oil it could be bypassing internally, but most oil cooler handle one or the other, what kind of anti-freeze are you using the high mileage can cause similar problems, best of luck to you.

  • 1 decade ago

    I blame the engine gnomes.

    This one sounds like a stumper. If you are losing that much ATF, it can't be good. you should try to put some Lucas additive in it and see if that helps slow the leak.

    There are some pretty easy explanations... all of which involve hallucinogens.

  • 1 decade ago

    there is no way your trans fluid can get into the engine...there is no connection where it can happen. You obviously have a tranny leak...but it can't go into the engine...no way possible.

    there may be one explanation...do you have a transmission oil cooler on the vehicle...and if so...is it hooked up correctly...there is the possibility that something is not hooked up properly there and dumping trans oil into the engine....but if this was the case...I'd think engine oil would also be getting into the transmission....just a thought...other than that...nope can't happen

  • 1 decade ago

    I'm with Mr. Know It All on this one. It's not possible.

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