Tom and Ray: On a recent show, you recommended usage of any of the popular engine oil additives to fix a noisy valve lifter. I think you mentioned Marvel Mystery Oil by name. Since my '96 Dodge Ram has what sounds like a noisy lifter, I purchased that product. However, today I read an article from Road Rider Magazine (http://www.math.uwaterloo.ca/~rblander/snake_oil.txt
) that argues convincingly that there is no reliable evidence that any of these products offers any benefit whatsoever, and that there is much reliable evidence to the contrary. Before I return my quart of Marvel Mystery Oil to the store and ask for a refund, I'd like your opinion on the attached article.