The thermostat is located inside the thermostat housing at the end of the engine where the upper radiator hose attaches. For the 2001 Grand Cherokee, which could have a 4.0L inline-6, a 4.7L V8, or an optional 5.9L V8, the housing is the key clue and accessibility can vary by engine layout.
General location by engine type
Across the common engine options for the 2001 Grand Cherokee, the thermostat lives inside the thermostat housing mounted to the engine block where the big upper radiator hose ends. The exact orientation and access can differ depending on which engine your vehicle uses, but the thermostat itself remains inside that housing.
4.0L I6 (1999–2004)
On the 4.0-liter inline-6, the thermostat is housed in a housing connected to the engine where the upper radiator hose terminates. Access may require removing nearby components to reach the bolts and gasket.
4.7L V8 (1999–2004)
For the 4.7-liter V8, the thermostat remains inside the housing at the end of the engine where the cooling hose meets the engine. The exact positioning varies with engine bay layout, but the housing is the target for inspection or replacement.
5.9L (optional)
When equipped with the 5.9-liter, locate the thermostat housing at the engine end where the upper radiator hose connects. As with other models, the thermostat sits inside that housing and may require some disassembly to access.
In all cases, the thermostat is not a separate unit tucked away deep inside the engine; it is inside the housing that seals to the engine block and is opened when the engine reaches operating temperature.
How to locate and inspect the thermostat housing
To locate the housing and verify its condition, follow these steps:
- With the engine completely cool, open the hood and trace the large upper radiator hose from the radiator toward the engine.
- Where the hose ends on the engine, look for a metal (or metal with a plastic cap) housing secured with bolts. This is the thermostat housing.
- Check for signs of coolant seepage around the housing, a loose cover, or a cracked gasket. If you see leakage, the thermostat housing gasket or the thermostat itself may need replacement.
- If replacing, disconnect the hose, remove the housing bolts, lift off the housing, replace the thermostat with the correct orientation, install a new gasket, reattach the housing, and reconnect the hose.
- Refill the cooling system with the proper coolant type and bleed air as required per the vehicle’s service manual.
The process is similar across the engine options, though space in the engine bay can vary. If you’re not comfortable performing this work, a qualified mechanic can locate the thermostat housing and handle replacement.
Summary
On a 2001 Jeep Grand Cherokee, the thermostat is housed inside the thermostat housing where the upper radiator hose connects to the engine. The exact location is influenced by which engine you have (4.0L I6, 4.7L V8, or 5.9L), but the housing at the end of the hose remains the focal point for inspection and replacement. For precise guidance tailored to your exact engine code, refer to your owner’s manual or a factory service manual specific to the vehicle’s engine variant.
Quick takeaway
If you’re trying to locate or replace the thermostat on a 2001 Grand Cherokee, start by finding the large upper radiator hose end at the engine and identify the thermostat housing there. That housing contains the thermostat and is the starting point for any inspection or replacement work.