i just bought a 2003 Envoy xl with a 5.3 motor, besides a few other probs that i can figure out, intake gasket and such. when i turn the ignition on there is a steady tapping noise coming from under the dash, it is fairly steady and sounds like someone tapping under the dash with a metal object. it goes away after about 45 sec or so, but as soon as you start the truck the noise comes back the same. lookin for any help i can get as i have no clue what it is. i have looked on here for an idea but nothing helped. i tried unplugging the fan and pulling the relay but no change.
thank you in advance
thank you in advance