Hi

Evo 9, 2.3L engine, compresion 9.5:1, gtx3076.63, 490whp at 1.5bar
Head gasket is with metal rings and I have small leak on one of the cilinders between gasket and block.

What could be the reason?

Regards
Dimitar

 

The reason is the HG is blown. Time for a new one. While its apart, check the head and block surfaces for flatness, corrosion, pitting, etc..

 

Is third gasket. And everytime we inspect/machine work head and block. Fuel is pump gas.

 

Are coolant temps reasonable?

Have the injectors checked for flow.

Verify AFR is 11.0-11.5ish

Is it an atp kit or does it have a real exhaust housing

Use skinny fingers to tune it softer.

 

Which head studs are you using ? Are you using the correct torque down pattern and a quality torque wrench? I wipe the head and block mating surfaces down with brake cleaner before installing the head gasket to make sure both parts are very clean.

-pal215