Coolant Leak In the back of the EngineI’ve performed coolant pressure test at 16psi left it for one

I’ve performed coolant pressure test at 16psi left it for one hour, did not drop at all. Drove the car for two days, no leaks. Took the car out last night, drove it and still had no leaks when I parked it. Woke up next morning to a small puddle size of my hand. Reservoir still hasn’t dropped. I performed the leathal Gen 2 head cooling mod and burped the cooling system, before this happened. Please any help.

Put your hand back there and see it it's wet. If coolant leaked out of that head port overnight you should still be able to feel something slippery back there the next morning.

Are you positive it's the back of the engine? It could be leaking from somewhere else and running down. It might be worth getting one of those dye kits.

Pressure test the intercooler reservoir instead of the radiator system next.

Might be a dumb question but are you sure it's coolant on the ground and not water from the a/c system which drips near the back of engine on the passenger side?

Tried to get my hand back there. Couldn’t feel anything was wet. Looked back underneath and that small puddle had dryed up and everything underneath looks dry again now. Coolant and inter cooler both full to the top.

Coolant will dry up in a few days usually but if it dried up quick with no residue, it must have been condensate from the A/C.