My daughter grabbed the wrong jug to top off the oil and may have added a 1/2 to a full quartof 80w90, what could happen here? thank-you.
20% gear oil in a five quart motor?
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I would drain it as soon as possible. The EP additive (sulphur content) of the gear oil is not good for the internal combustion engine.
Bill in Utah
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Originally Posted By: Johnny
I would drain it as soon as possible. The EP additive (sulphur content) of the gear oil is not good for the internal combustion engine.
Originally Posted By: montero91
My daughter grabbed the wrong jug to top off the oil and may have added a 1/2 to a full quartof 80w90, what could happen here? thank-you.
Excellent excuse to change the motor oil and filter. Gear oils have different friction modifiers than motor oil and have a low TBN.
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Agreed, get it out of there ASAP. 
Then I would do a shorter run with some cheap regular oil and then change out and go back to what you are used to.
Then I would do a shorter run with some cheap regular oil and then change out and go back to what you are used to.
Sorry guys now she says it was the other jug, they are all blue from wallymart, so it turns out it was old atf in an oil jug any hurt with this?
ATF won't do any damage, but I would change out your oil.
Thanks because I just changed the oil about a month ago and the atf came out of the tranny( the pan holds about two quarts and I do this every oil change)
Originally Posted By: Junior
Originally Posted By: montero91
My daughter grabbed the wrong jug to top off the oil and may have added a 1/2 to a full quartof 80w90, what could happen here? thank-you.
Originally Posted By: sunfire
Today is Saturday you know what you have to do.
It's fine for another few 1000 miles.
If you wash the motor out with brake clean there shouldn't be any harm.
Originally Posted By: Drew99GT
If you wash the motor out with brake clean there shouldn't be any harm.
Just change the oil ASAP and don't worry... 
I think it's time to weld the hood shut and do her LOF's with a vacuum machine from now on.
Someone said it above.
Change the oil & filter with some cheapo stuff. Go drive around a while and then change it again with the normal oil & filter. Since what's in there seems to still be a mystery I wouldn't drive it all all until you've done this. Better safe than sorry.
Blame it on her teacher. Change the oil.
Time for tough love?
Either way, no harm in the short term. You don't have to change it out yesterday.
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