Haven't tested the cap or bottom hose. Here is the latest.
Yes, after a freeway run to work, about 15 min at speed it's overheating & won't bring itself down. Work commute is about 20+ min total. I put my hand over the radiator & it feels cool. Still has coolant in it.
So, Last night I took surface streets home. about 30min. It ran a little warm until about 5 minute from home, then it spiked. Turned it off & let sit for a couple minutes. Start it up & it quickly drops into the warm area again, not hot. Ran it the rest of the way home. A couple times when I revved the motor for a seconds, the needle would drop a few degree. Then work its way back up to where it was.
It's seeming to me like there isn't free flow of coolant. As if it's restricted then , completely clogs up at times, when its warm.
Sound logical?
The radiator looks clean, & the old
antifreeze didn't show signs of excessive sludge?