OEM 2001 Jeep Grand Cherokee Thermostat

2001 Jeep Grand Cherokee Thermostat Parts and Q&A

• Q: How to Maintain a Thermostat on a 4.0L Engine on 2001 Jeep Grand Cherokee?

  A: Never loosen the radiator draincock when the thermostat is being serviced on a 4.0L engine since the hot and pressurized coolant could burn you. Drain the coolant into a clean vessel to reuse it until you reach below where the thermostat housing is installed. Use the correct tools, whether it's the Snap-On clamp tool number HPC-20 for the larger ones or number 6094 designed for constant tension hose clamps and put on your safety glasses each time. In case you need to use new tension clamps, buy and fit those with the corresponding stamping as the previous ones had. Pull off the radiator upper hose and heater hose from the thermostat housing, unplug the wiring connector from the engine coolant temperature sensor, get rid of the thermostat housing mounting bolts, the housing, gasket and thermostat and throw out the old gasket. Before you install the thermostat, scrub the sealing surfaces and make sure the thermostat arrow and opening on its outer flange point up toward the recess in the engine cylinder head. Carefully install the replacement gasket and housing for the thermostat, using 22 Nm (16 ft. lbs.) torque on every nut and bolt so the housing doesn't develop cracks. Connect the hoses again to the thermostat housing and plug the electrical connector into the coolant temperature sensor. Quickly tighten the draincock after use and then fill the cooling system with the proper mixture up to the right level. After that, engine starts and leaks are checked.