My 97 f-150 4x4 4.6L with 200k miles has a spark knock. I had the Bosch platinum +4 plugs in it. And it pinged really bad with those. If I fill up with 93 octane it doesn't ping. I ran out all of my 93 and filled back up with 87 and it went back to knockin. Saturday I replaced the Bosch's with motocraft platinum plugs, put fuel injector cleaner in the tank, and now it does not ping nearly as bad, but it is still there, Especially around 3800+ RPM.

A chevy guy I work with told me about a knock sensor on the side of the engine block. I had never heard of this before and was woundering if this may have something to do with my ping? Could someone please fill me in on Knock Sensors?

My air filter is clean, i had a new fuel filter put in last year.

What can I do about my spark knock? I think my plug wires are fine they looked new when I bought the truck w/ 168k miles on it. How would I know if the plug wires needed to be changed?

Please help this knockin is drivin me crazy...er!!

 

You can try cleaning the MAF. It could be a bit dirty causing a lean condition.
There is a link to how to do this in the FAQ thead.