Explorer ticking noise

[Mustangman4o8]

Hey guys I've had this 1999 explorer since summer now and it's had this ticking noise. I've been trying to locate where it is and if it'll screw something up. So far all I know is it runs really smooth and doesn't miss a beat. But when I take the oil fill Cap off its louder inside. I've also heard it could be the lifter or the timing chain. Any suggestions?

 

[Rick]

Ticking is usually valvetrain related. A bad lifter is definitely a possibility as is a bad rocker arm.

 

[Rick]

BTW, a poor mans auto stethoscope is a long screwdriver.... Put the blade to the valve cover and the handle to your ear and you will be able to hear the valve train in action. It should help isolate which side of the engine the problem is on.

 

[Mustangman4o8]

Wouldn't a bad lifter or valve Train cause the engine to run rough?

 

[morbid81]

what engine?