Hello, I have a 350 olds engine, My top radiator hose carriers a lot of pressure, I have switched out thermostats, I went for a 180 to a 160 degree with no change in the pressure, also switched radiator caps, it had a 20psi on it and I put a 16psi. it does not overheat, just carriers a lot of pressure, Not sure if bottom hose carriers pressure or not, It's a stiff hose with a spring in it, Anybody else have this problem?? Any suggestions? Thanks

 

Problem?

Your cooling system, as you have surmised, is a 15- (or 16-) pound system, and should have a 15 or 16 pound cap.

That means that when the system is operating properly and the car is fully warmed up, it should have 15 or 16psi in the cooling system.

That means that when the can is fully warmed up, the hoses should be essentially rock-hard, just like every other car made since the 1950s.

If your hoses are soft when the car is warmed up, that means you have a problem.

- Eric

 

X2


bill

 

Actually, the cap is set to open at what ever the presure rating is. This can be anywhere from 6-20#, at that point puddles form on the ground. So the operating pressure should be less than what the cap is rated at.

The thermostat is rated for the minimum operating temp of the engine. Your engine is designed to run with the 180 deg, putting a 160 in there just changes the amount of time it takes to reach peak operating temp by opening earlier. Whether you have a 180 in there or a 160, on a 100+ degree temp day you are still going to max out at 200+ deg's in traffic.

The reason the hoses are hard is because as the temp rises, water expands, and it builds pressure. This pressure allows for a higher temp before water boils. So generally a car won't boil over until about 240 - 260deg.

 

For a piece of mind you can also start the Engine with the radiator cap of and smell the water,if it smells like exhaust gasses and/or have really tiny air bubles then you maybe have a leaking headgasket that puts extra pressure on the cooling system.