So i have a 91 HF and i am considering using seafoam. I have heard that it really cleans out the engine. I am weary of it because of a number of reasons. 1. my car runs fine right now. If there was something wrong i might consider using it. 2. my rex has 204,000 miles on it. I am sure there is a lot of sludge built up in the engine but as long as it is running fine I don't really think I should mess with it. 3. I am worried that if i use seafoam there will be parts of sludge or something that will come loose and damage the engine. I might consider using it in my gas tank but not the engine. What does everyone think? Has anybody ever heard of anything really bad occurring because of seafoam?