hey guys i have a wierd thing going on, i have a lot of pressure in my coolant system when i start the car and drive it a quarter mile and turn it off. i take the cap off and it blows like crazy! and the water is still cold. the other thing i noticed was that i have pressure after the car sits over night? should i always have this pressure in the coolant system?

 

Nope, I would do a cylinder leakdown test to check for a bad head gasket.

 

yea all cylinders are fine with the pressure test....

 

A little pressure is normal as the coolant heats up.
The only other thing would be a whole lot of air in the system. I only run a 7psi cap and it has never blown from pressure.

 

yea i know i should have some pressure, but i have pressure way before the car even gets warm, i can still touch the headers cold haha. i would say i have a leak in a line somewhere but that wouldnt hold the pressure then.

 

head gaskets. Your supercharged, running boost, and have compression in the coolant. happens all the time.