This weekend I flushed out the coolant and ended up changing the radiator for the nice metal one after discovering a cracked plastic inlet. However, the thermostat I bought at a local parts store does not have the little pin valve that looks like a partially bucked rivet (for lack of a better description). I decided not to install it. The heater works well & the temp needle has a mind of it's own - I need to do the temp board bypass, the needle is typically at 9:00.
The upper hose gets very hot, this morning the lower hose was cool.
Are these signs of a failed thermostat?
Does the lack of that little loose valve matter? I'm assuming it is to prevent trapped air.

Thanks,

Mike