oops I put a bit of tranny oil in my engine... how bad is it?
 

I was rushing to top up my oil in my 1985 300TD, in a poorly lit garage, and I accidentally added probably about a half a cup of transmission oil before I realized what it was.

I then proceeded to add about another half a pint of proper engine oil.

What do you think. How bad is it to have that small amount of tranny fluid in the engine?

Better I do an oil and filter change now? Im due for one in about 2 months (or perhaps 1000 miles.) could it wait you think?

Thanks

Your D will use it to help clean out any built up gunk

Don't worry about it.

the engine holds 2 gallons... 1/2 of a CUP is NOTHING.

I thought so. I wasnt too worried, but again, I would rather get a second opinion.

Thanks for washing away any doubt....I will drive on

I just changed the oil in my boat's gear box. It said I could use either ATF or SAE30 engine oil.

I don't think you have anything to worry about!

You're fine. Putting some ATF into the crankcase to clean the engine out is an old mechanic's trick, and I have done it many times with no problem.

I'll agree that it's not an issue. In fact, ATF is a VERY good detergent and will wash out a lot of gunk. We used to use it with cars with sticky hydraulic valve lifters to get the crap out of them and it often worked.

You may see more junk than normal with your next oil change.

Dan