Benefits and/or drawbacks to each one? I think my cap is bad and when I went to look up the OEM one to replace it I discovered they came in 13 and 16 psi versions. The cap on there now is a Belknap 16psi. The FSM was no help since they only list the range and both caps fit in that range.

 

Those are the pressures at which the pressure relief valve in the cap will allow coolant to pass to the recovery tank. Later when your system cools and contracts, that coolant will be drawn back into the system via a check valve in the cap. Also that vacuum is why some of the hoses have springs inside.

The lower will let more pass sooner. I've seen caps ranging all the way from 12 to 20, so 16 happens to land right in the middle. I suppose there's a relationship between the capacity of the recovery tank and the pressure of the cap.

Water actually does a better job of picking up, holding and dumping heat, than coolant, (ethylene glycol), hence the 50/50 mix. With a higher ratio of water, and a lower boiling point a higher pressure cap might be desirable, and visa-versa.

So, I don't have a clue. Maybe djb will chime in. 16 sounds good.

 

A 13 lb cap raises the coolant boiling point to +/-251F @ sea level....a 16 lb cap raises boiling point to +/-260F.....about 3 degree increase for each 1 lb increase.

 

So if I think I might be running a little hot the 13 would keep it running cooler?

Right now it's running a bit past the mid point on the gauge and I get a whiff of coolant smell(but no obvious sigh of coolant)when I open the hood. Wifes Sebring did that once and a new cap cured it.

Just curious...thanks.

 

It's the thermostat that controls minimum temp. Say a 195*, will open around operating temp, letting coolant circulate to the radiator.

 

Negative....251F vs 260F is overheated either way. U must have a properly functioning rad cap (it has 2 valves and 3 sealing surfaces that MUST all 5 function correctly) BUT the main cooling system components are the radiator, water pump, fan clutch and t-stat. Running past the middle seems hot with current cool ambient temps. System should be pressure tested to expose the leak so it can be repaired. Smelling coolant is a sure sign of a leak and leaks only get bigger when u least expect it.

 

Defiantly the "whiff" gives it away. Unless you just spilled some, it's leaking somewhere. Hopefully it doesn't hit you when you turn on the defroster.