How do you change the thermostat on a 1993 Nissan Quest?
Follow the lower hose from rediator to engine. The hose is connected to the thermostat at the engine. Remove the hose,(collect fluid) take out the two bolts, remove the thermostat and clean the old gasket off the engine. Use blue gasket seal and install the new thermostat.
According to the history of the Nissan Quest Vg30e engine from 1993 thru 1998 these group of engines were non-interference engine, so if the belt breaks it will not damage the valves. This feature was demanded by FORD from Nissan before FORD agreed to used this engine in their ViLLAGER and Nissan Quest vans in the time of their joint venture.
I found the thermostat on a 1993 Nissan 240SX (KA24DE, 2.4liter DOHC). It is approximately 2 inches to the left, and an inch or two above the fan pulley. There is a large hose going into it. The large hose coming from the top of the radiator going into the engine block DOES NOT go to the thermostat, but where IT enters the engine block you will see a small bolt for bleeding air from…
follow the top radiator hose to the engine. that is where your thermostat is. you will have to drain the radiator, remove the engine side of the hose and remove the thermostat housing to access it. remove thermostat clean mating surface of housing and engine, install thermostat, install housing, secure radiator hose, fill with coolant. start engine and check for leaks.
Find the upper radiator hose then follow it to where it is clamped to the engine. That mounting is the thermostat cover; remove it and the thermostat is inside. When you replace it make very sure you put the new one in correctly. It should be marked or have a picture of how it faces in the instructions.