Originally posted by tcodi
do valves start to make noise when they get out of adjustment. I'm asking about by grand cherokee v-8 with 150,000 miles on it. For some reason when I step hard on the gas, even if its on the highway and the rpm's stay constant, I hear the rapid tapping of something.
It has nothing to do with rpm, just throttle level. I don't know what this is.
Could the valves be out of adjustment from the age?
sounds like spark knock to me, try a better grade of gas and see if it stops.