Horrible rattle?

[agressivedsm]

So long story short, i have a 6/7 bolt combo with bc272's and im bored .20 over. Engine has about 1500 miles. Was running perfect last night. Pulled into garage and started it this morning and there was a rattle similar to valvetrain noise when there is no oil pressure. The idle was also very rough. Pulled the valve cover and everything is super clean and tight. Sound seemed to be echoing through the intake manifold. Tomorrow im going to borescope and do a compression test. Also...... It seems i cant build any boost 2psi tops although i didnt hammer it due to the ugly noise. The oil squirters seem to be perfect. Checked turbo shaft play and bearing and all is good. Plugs have some carbon build up but are dry. Rattle speeds up with rpm but doesnt get any louder. Any ideas?

 

[NHerron]

Does the sound change with the clutch pedal applied?

Could it be one of the accessory belts?

Exhaust leak? To check for an exhaust leak go pick up some Seafoam from any auto parts store. Pull a vacuum line off with the engine running and suck up 1/4 of the can. Shut the car off quickly after. Let it soak for at least 20mins. After that start it up and see the smoke show! Besides being kinda cool to see, look around the engine bay for any smoke. That stuff WILL let you know where the leak is.

 

[agressivedsm]

Not the belts. Doesnt change with clutch pressure. Maybe ill try your seafoam trick tonight.

So i did a compression check 175 175 160 175 I borescped and saw nothing unusual exept...... The fact that i bought this engine as a .20 over motor. The pistons are cast as 63dTf1 which as far as i know are stock 2g pistons. Now if a guy were to use stock 2g pistons with a bored over motor he would have had to use oversized rings. Anyone hear of people doing this? At this point I am leaning towards piston slap. Anyone wanna put in their two cents?

 

[agressivedsm]

Pulled a lifter out today. Still has the oe 1mm lifters. Going to try some 3g 3mm lifters first before going too deep. Anyone here have good luck with ITM from parts dinosaur?