What happens if you put it in your oil after you change it and run it for 3000 miles? Does it hurt anything or just keep cleaning?

 

Don't do it. If you put it in your oil, you only want it in there for max 100-150 miles and then change it. For one thing, it'll eat away at all your seals after a certain amount of time and you'll be leaking at every orfice.

 

Best thing to do is put it in like 500 miles before an oil change to loosen up all the excess crud. The seafoam actually thins the oil so it's not good to run it for a long time.

 

I'm thinking of adding sea foam to my oil a hundred miles before my next oil change. How much do I add? The whole bottle? Then drive normally?

 

1/3 can max and 100 miles is overkill.

I do 1/3 in the oil 10-20 miles before oil and filter change, a third in a full tank of gas, and a third in my intake.

For the intake I dump a little in with the car off, start it, rev til it stops smoking and repeat til Ive used a third of a can or it doesnt create smoke anymore.