Blocking Radiator ???

[vettestr]

Hey Dan,
I noted on cold start up your engine heats up to 180* but then drops 20* when t-stat opens and normalizes at the lower temp of 160*. You also said you verified opening temp on the stove. You also said your oil temp is concurrent with coolant temps (each at 70C) 158*.

Before hanging your hat on these numbers from a cold start I would run long enough to get everything to settle and fully heat oil and engine bay with coolant at stable readings. Oil temp will be about 20* above coolant but your sensors locations can also affect readings. You need to drive the car not just run in the driveway. Gauges and sensors all rolled up with the +/- allowed still have you at a reasonable reading. Is oil pressure real high? If it ain't broke do not fix it.

After a drive if the numbers look the same and you still have a temp of 160* maybe you are bypassing the t-stat with heater hoses or a bypass hose around the t-stat. I would rather see her at 180* but 160 beats the hell out of 220 or 230.