engine knock

[vtlaxplaya16]

ok i have a 1990 talon tsi awd, it is all stock. When you start the car and let it idle, it sounds fine, no problems at all. As soon as you raise the rpm to 1500 it starts knocking, as you raise the idle higher the sound continues to increase in speed. It sounds like it is comming from the very top of the motor, but the sound is more harsh than lifter tap. It is an actual knock. any ideas on what it is anyone?

 

[vtlaxplaya16]

*update*
its more of a rapid ticking/clicking than a knock, and i took spark plug wires out one by one and the noise is still audible

 

[vtlaxplaya16]

i know someone out there has to have some feedback, even if its a little, anything would be appreciated. I was wondering if a broken lifter would make that kind of noise.