I put water into the place where oil should go by mistake. The warning light on the dash went off and I drove for an hour to get home. What should I do about this, there is now some gunk on the dip stick and around the oil filler cap?
Engine oil is designed to hold water in suspension as an emulsion. Do an oil and filter change as recommended and refill with new clean oil. It should be fine.
A lot easier to sort out than putting oil into the places where water should go! Just imagine the mess if you put oil in the washer water bottle or the radiator !!
This reminds of something that happened many, many years ago. I used to have a Beetle and when my nephew was very young, I caught him just in time, as he was about to pour some water into the oil hole !
I am with everybody else here....take it to a garage and get an oil change done pretty quick !
As most other people have suggested, replace and renew the oil and filter then give the car a longish run to help clear any condensation both within the engine and it's associated pipework. You might have to do this oil and filter change a couple of times until you see no further emulsion either on the dipstick or under the oil filler cap. Try to avoid any shorter journeys until you have done this. By shorter journeys I mean less than around 8 miles as it takes around 10 miles to get the oil temperature up to full operating temperature. I can't emphasise enough...get some heat into that engine to boil out the water/condensation.