Knocking at noramal operating temp

I am looking for an answer for this problem. I have a 1998 explorer AWD with a 5.0L motor. This vehicle will knock at high or lower speeds. This knock sounds like a octane knock or like the veh has jumped time. The local Ford Dealer has advised that this is a normal operation. The dealer calls this a spark knock. I have changed the spark plugs & wires which did nothing. Does anyone have any suggestions? Thank you in advance! Pony Puller

haynes repair manual has a troubleshooting guide in the front, says can be caused by plugs, injectors,restricted exhaust,etc. try a injector cleaner. in the gas..up your octane..

Thanks for the info. I have tried all except for having the fuel injectors pressure tested & cleaned. Nothing seems to help. I really like my Explorer. But this is driving me crazy. Do you think it could possibly be the o2 sensors?

throw in a quart of tranny fluid. it will quiet the knock. mechanuts have been doing this for years

Thanks! I might try that when I need my ned oil & filter change.