I have a 92 dodge caravan 3.3 152,000 miles

At the beginning of the summer i changed thermostat and radiator cap For some reason someone put a 13 psi but book calls for 16 psi so i switched it and coolant and ever since i notice that on a hot day or when i use the Air Condition when i shut the vehicle and pop the hood the Coolant in the overflow raises and sometimes boils and sometimes comes over. Is it normal for it to boil like that. Temp Guage always normal. Anyone have any input?

 

They might have noticed a head gasket or head problem and lowered the pressure to prevent crossover. A higher pressure cap increases the temperature at which the fluid will boil in the closed system. Are you using any more coolant since putting the higher pressure cap back on?

 

I don't really understand what you mean by using more coolant radiator is full to neck and overflow stabilized itself right below low line when it is hot outside or i use the A/C for a while the overflow comes to the top and boils in the overflow it was coming over but not anymore because it stabilized itself. Both cooling fans work perfect. Head gasket was replaced around 30,000 miles ago