lude98SH

Ok the cooling system is running a mugen fan switch(i know not worth it), oem thermostat, brand new water pump and a fluidyne radiator. The coolant level holds at the top of the radiator. When i datalog the car never goes above 200 degrees or so, runs constantly around 180. However i will turn the car after driving awhile and come back a few days later and the radiator will still be under pressure when the cap is removed. The coolant res is filled to the upper mark and hasnt moved more than an inch in the last 9 months. However it is mounted above 8 inches lower than the radiator neck. The hose is connected in the overflow and connected to the overflow from the radiator. Isnt the system supposed to equalize the pressure once cold ?

teambk8

have you replaced the cap recently? The spring could be too stiff to allow pressure into the overflow... thats my only thought

lude98SH

thats mine also. Its a spoon cap which i know a few people that have had problems with them.

Giant_Bean

Make sure that the hose between the radiator and the overflow is not plugged, I had a similar issue, and wound up blowing up a lower hose becuase of it.

lude98SH

nope its clear

teambk8

try an autozone ghetto cap and see if it works? Thats really weird that even after days it keeps the pressure. It only makes sense that its the cap... maybe there is air in there blocking the pressure from escaping? ( I don't know if that makes much sense but its really my only other thought, give me time for my handful of brain cells to come up with another)

G2IntegraGS

Mine holds pressure too, I didnt know it was a bad thing tho.

teambk8

Its not a questions if it holds pressure or not, but does it stop holding pressure upon cooling?

DCFIVER

Cap.