What about adding to the crankcase?Should i add Seafoam to a '94 geo prizm before an oil change?Adding it to the oil IS adding it to the crankcase.
If you are going to do it, add 3-4 ounces to your oil probably 100-500 miles before your oil change. It'll be pretty diluted at that level so I wouldn't worry about it causing physical damage to your engine.
Why are you wanting to add seafoam? Is there a specific problem you're trying to cure? One thing you need to be aware of is that by cleaning sludge out of your engine you could be creating oil leaks. It is an old car and sludge may be essentially sealing up the last 14 years worth of oil leaks. Just a warning.
Another option you have is to add about 1/2 quart of automatic transmission fluid to the oil about 500 miles before an oil change. ATF has TONS of detergent in it and will clean out your motor's insides quite well.Should i add Seafoam to a '94 geo prizm before an oil change?That car is almost 14 years old, I would stay away from seafoam.
