Hey Terry Vaughan,
A quick test that might be worth a try.
Can you please get someone to raise the engine revs while you watch the two radiator hoses?
Transmission in Park, park brake on.
You are looking for if one of the hoses collapses when the engine revs rise.
Some radiator hoses have springs inside to stop them from collapsing, In which case you may need a new rad hose. They also get soft with age.
Then a flush and a new thermostat are a great idea too.
Hope that helps.
Regards, Joe
Saturday, April 6th, 2019 AT 12:29 PM