How to Replace a Thermostat in a Grand Caravanby Chris Moore
The thermostat in a Dodge Grand Caravan is an important piece of the heating and cooling system, as it regulates the amount of coolant going to the system. If the Caravan's engine takes a long time to heat up, the thermostat is likely stuck open. If the engine is hot but the upper radiator hose isn't, the thermostat is stuck closed. The thermostat, which is mounted to the engine block and connected to the radiator with a hose, needs to be replaced if it is stuck in any position.
Disconnect the Caravan's negative battery cable. Drain the engine coolant into a clean container by removing the drain plug from the radiator, then at the engine block drain plugs. The engine must be cool before you do this.
Locate the upper radiator hose and follow it to the engine. This hose will be connected to the thermostat housing cover. Disconnect the hose from the fitting by loosening hose clamp. If the hose is stuck, twist it with adjustable pliers to break its seal.
Remove the housing cover from the thermostat by removing its fasteners. Tap it loose with a soft-face hammer if it is stuck. Expect some engine coolant to spill out as you remove the cover.
Disconnect the old thermostat from the engine. If the van has a V6 engine, a stock thermostat is "staked" in place with small bits of material in two places that you must remove. Clean the mating surface after removal and remove all traces of the old gasket.
Install your new thermostat in the exact same position that the old one was in, placing its jiggle pin at the 12 o'clock position and its spring end going into the engine. Install a new gasket on the thermostat, orienting it in the same way as the old one was.
Reconnect the housing cover, tightening its bolts to 21 foot pounds. Attach the radiator hose and make sure the hose clamp is securely tight.
Connect the negative battery cable. Refill the cooling system through the radiator filler neck until the neck is close to overflow, then refill the reservoir's level to between the "Full Hot" and "Add" marks.