Mocal inline stats open at 80 degrees when using an inline stat you need to fill your cooler core with oil prior to fittong to allow for the pressure drop when the thermo opens for the.first time. @ wallace you jave this problem as you run a.sanwich plate which requires it to be slightly open at all times which inturn allows oil to return to the engine if it closed your engine would.be starved of oil. just out of interest do you have an oilpressure guage if so what does it read on idle as i was under the impression that sandwich plated hamper the oil pressure as they are sort of half open