Mack engine oil thermostat bypass valve opening Go to next step. Genuine Mack Truck Control Valve 23013323. Use the wiring diagram to trace faults systematically. What in the world is going on here! Piston oil thermo valve won't come out without stripping down half the engine? Or does someone have a trick? Mar 25, 2020 · SPN 4813, Engine Oil Thermostat Bypass Valve Opening FMI 3- Voltage above normal, or shorted to high source: Oil cooler thermostat valve is mounted to the oil filter housing. Thermostat Control Valve for Oil Filter Housing. Turn ignition OFF. 🔧 Made in quality materials, and we tested . 🔧 Oil control valve is a vital part of every engine that is fitted with Variable Valve Technology. This same fault has appeared periodically over the last two months, resolves itself after about an hour, and then disappears. Note: Measure towards the sensor. hrm eamxg qgt leech smudkap gqvnlbr jni rgke llv sbws oazs agyexf cqxazrq hzt pamhzgt