An optional engine block heater is available in the Grand Cherokee (standard equipment in Canada). The heater is equipped with a power cord. The cord is attached to an engine compartment component with tie-straps. The heater warms the engine providing easier engine starting and faster warm-up in low temperatures. On the 3.7L and 4.7L engines the heater is mounted in a core hole of the right side of the engine cylinder block, in place of a freeze plug with the heating element immersed in engine coolant.
The 5.7L/6.1L engines have the block heater located on the left side of the engine below the exhaust manifold in the rear of the engine. It is not immersed in engine coolant but makes direct contact with the block.
Connecting the power cord to a grounded 110-120 volt AC electrical outlet with a grounded, three wire extension cord activates the heating element warming the engine coolant.
If the unit does not operate, possible causes can be either the power cord or the heater element. Test the power cord for continuity with a 110-volt voltmeter or 110-volt test light. Test heater element continuity with an ohmmeter or a 12-volt test light.
Mopar engine block heater kits
Engine Block Heaters keep the engine warm for easier starting and quicker warm-up. Features include special plug-in wiring designed for each application and is the same as the production heaters. Depending on engine size, 450 to 600 Watt heaters.
*Adding a block heater to a 6.1L engine is a somewhat difficult process due to the limited amount of room to work with in the mounting area. Installation will require grinding down the cylinder end of the block heater (beveling it around the edge) to get it into the engine block mounting hole. If the heater cylinder was just 1/8″ or so shorter, installation would be a snap. Access is best via the driver side wheelwell.
WARNING: Do not operate engine unless block heater cord has been disconnected from power source and secured in place. The power cord must be secured in its retaining clips and routed away from exhaust manifolds and moving parts.
Engine block heater, Jeep SRT8 6.1L. View from fenderwell.