Additional test done this morning. Started the engine cold with radiator cap on. Pressure builds up in the cooling system with the engine NOT WARMED UP YET (after approx 1 minute). yet still no contamination in all fluids.

Hayyyy!!!! it must be the HG again.....

Any idea folks if the head bolts on a 4d56 torque-to-yield or not (i.e. reusable)?

Last year was my first time to change gaskets, so i might have affected the plastic deformation of the bolts since i did not replace them.

I torqued the bolts to specs then 90 deg + 90 deg. is this right tightening sequence?