autowrench...good advice!! ive been doing the distilled water staem clean via the brake booster cable to engine for years now..works WAY better than any chemicl out thier. I used to use mopar combustion chamber cleaner, and manyt imes have done the seafoam through intake method, and it makes an enormous amount of smelly smoke...
as autowrench said.. get about 24-32 ozs of distilled water,. yuo dont wanna use tap water as it can cause rust and mineral deposits much quicker. boil it. pour into an old spray bottle, rev the engine at about 1500 rpm, and spray the hot distilled water into the throttle body, or better, after the PCV valve or brake booster to engine head line. but..remember to let the egnine cool down, replace the spark plugs and oil and filter.. to evacuate any unbunred water and yuo really dont know how much crud may or maynot come out* the carbon, if any, may interfere with teh electrodes on bottom of spark plug, carboning them up, hence forth replace em. i do this method once a year.
sen many pics of engines using this method, SPOTLESS. however, if yuor car leaks oil, as all eventually will..yuor best bet it to go with a good high mileage engine. like 5 years ago, i wa using mobil 1 5w30 synthetic, a true syntheitc*. after abuot 8 months, and 130,000 miles on engine, guess what. came out one day, and discovered about 75% of a quart of fresh oil i changed 3 nights earlier, under my car. mobil oil is known for its cleaning prpertys, but it sucks as a lubricating oil. it cleaned my engine up too well lol. so went witht he high mileage stuff, so the seals re sweel, and replaced the rear seal as well. mobil get bad reviews, becasue it repeatedly has failed the ball bearing test* a friction test done by the auto industry on psitons/cams in engines. mobil will clean everything up, including varnish* but not something ide persoanlly use long term.