After my oil pressure was dropping too low with the 5w-30, I switched it to 10w-30 with no change in pressure. And engine is still getting too hot even after getting new radiator, thermostat and hoses.
While this may not be related, I noticed that the radiator fan is NOT coming on at idle. It will come on when I turn the A/C on, but not when engine is running hot at idle.
Bad temperature switch in the engine block?
My Fiero: 1986 Pontiac Fiero GT, V6, 4-speed manual