did you tension it up correctly?
1. slide "locked" tensioner into bore
2. screw in outer tensioner housing all the way
3. unlock the tensioner using an allen key or very small flathead ( anti clockwise direction )
4. screw in retaining plug ensuring filter is on the end.
If that doesnt help you there could be a few things causing it, the most extreme would be low oil pressure on idle, next would be incorrectly installed chain, next ( most common ) would be that the O-Ring on the back of the timing cover is blocking the tensioner oil feed hole. Did u hold the O-ring in place with some grease?
Anyways I would try re-tensioning the chain
Oh and I hope you replaced all three guides while you were there
Lets go find that Hotdog tree I planted
Lowered EF Futura
Black Steelies ( too cheap to buy proper mags )