Because of the potential for variations in location due to slight manufacturing differences or modifications, it's best to:
1. Consult your Jeep Grand Cherokee's owner's manual: This is the most reliable source. It will specify the exact location of the engine number.
2. Check online forums: Search forums specific to Jeep Grand Cherokee owners (e.g., JeepGarage, CherokeeForum). Other owners may have pictures or more precise instructions.
3. Contact a Jeep dealership or mechanic: They have access to service manuals and are experienced in locating vehicle identification numbers and engine numbers.
Remember that the engine number is different from the Vehicle Identification Number (VIN). The VIN is located on the dashboard (visible through the windshield) and on the driver's side doorjamb.