Big Red Farkas

Hey guys, i have a 1992 f150 with the 300 big six powerplant. Out of nowhere a few days ago i left the truck idle after going for a drive and noticed a loud ticking tapping sound. Its coming from the engine bay but i cant narrow it down to anything. It only occurs at idle and if i rev the engine, it stops for about 10 seconds. After 10 seconds, i hear a loud clank then it starts tapping again. I can repeat this on command after driving for a few miles. I am at total loss and im afraid if i drive it, it will get worse. Thanks for any help, its appreciated. By the way, i have not recently done any work or modifications so that xonfuses me even more. Thanks.

Big Red Farkas

Sorry guys, I just realized this is in the wrong forum section. How do i move this thread.

glen66

You have a lifter bleeding down, at idle the oil can't keep it pumped up, when you bring on rpm the oil pressure comes up and then is able to keep the lifter pumped up and the ticking noise goes away. Remember if you change one change them all, good insurance.

joshtowal

Lifter bleed down or timing chain is worn and loose. Did you have your oil changed at the same time this started? A mechanics stethoscope will help you figure out where it's coming from.