How do you change the thermostat in a 92 Cadillac deville?

Answer 1

Repair instructions given here are for all front wheel drive Cadillacs from 1985 to 1995 with the 4.1, 4.5 or 4.9 motor. (On some models it is helpful to remove the air cleaner)

1. Start with a cold engine.

2. Remove about a gallon of coolant into a clean container (you can reuse it). I open the radiator cap and use a hose to syphon it out, but you can drain it from the valve on the driver's side plastic tank of the radiator if you want to.

3. Remove the two bolts from the thermostat upper housing (it is usually black steel and the radiator upper hose is clamped to it).

4. The thermostat (and gasket) should just pull out, if you have to use a pair of pliers, make sure all of the gasket comes off of the lower (aluminum) housing.

5. Install the gasket on the thermostat, there is a grove on the inside of the gasket that the edge of the thermostat must fit into so that it is wrapped around the edge of the thermostat.

place the thermostat with gasket on the edge in the lower thermostat housing making sure that the gasket is inside the channel and that the big round end is toward the engine (usually brass in color).

6. Replace the upper thermostat housing on the lower housing and tighten the screws.

7. Replace the coolant in the engine (and the cap if removed) and you are done!

Cadillac Man