aktif8

1.8t, tip, 64k miles

at idle (all of a sudden) the engine is making a "clacking" noise, and when revved, sounds really loud, kind of like a lawnmower, until the revs hit about 3k, at which point the engine sounds like normal again (and no clacking).
boost is building and hitting like normal(according to the butt dyno and my boost gauge,) but power seems to be reduced until the clacking goes away.

could this be a valve problem? the car was just dropped off at the dealership, and it's under audicare, but i'd like to have some idea of what i'm dealing with here.

thanks mucho for any help, guys.

keith

RKA

What was the car in the dealership for? What year is your car? Have you changed your timing belt?

aktif8

dropped it off for this prob, 98.5, original timing belt.

RKA

It resembles metal to metal contact too much, and that's never good. Wait and see what the dealer comes back with.

dpd

is it a tapping noise or a knocking noise?does it sound like it's up at the top of the motor or down towards the bottom of the motor?if it's a loud clicking noise most noticeable towards the rear of the valve cover,near cylinder #4,it's most likely the hydraulic tensioner for the camshafts inside the valve cover.that would explain your torque loss below 3000 and our noise.power loss because cams are retarded due to tensioner leaking down.fix.remov camshafts and replace tensioner.----dpd