Ok I just bought a 1997 Sunfire GT with a fully built, turbo'd motor and I'm having a issue that I'm not sure what to do about. I have talked to the previous owner and mechanic and here's the story.

Rebuilt motor put in and the chain (new chain/sprockets/guides/tensioner) starts making a racket after a short time. They pull the tenisoner and replace it with a "new" style which seemed to fix it up. However now on warm starts the chain will rattle/clatter for a minute or so. It only does it on warm starts, you can almost here the tensioner snaping into place after a minute, at least I think thats what it is. It goes from noisy to quiet almost instantly when it changes and then doesn't make the noise again.

The motor did get a few oil system mods, the machine shop "opened up" the galleries and modified (higher relief spring?) the oil pump and there is a piggy back oil cooler with larger oil filter (ford truck style). There is also a oil pressure gauge with the sender tapping into the back right of the block I believe.

The vavle springs are higher compression aftermarket ones, could this be putting extra strain on the tensioner?

OIL - 5W50 (I'm thinking of switching but this is what it came with)
OIL PRESSURE: cold idle 60-70psi, warm idle 25psi, higher rpm warm 45-60

What should I do? Is there something that could cause this other than a bad tensioner, seems unlikely that 2 would fail within 3000km? can the tensioner be modified in any way to improve it?