How to Change the Thermostat in a Nissan Maxima

As with most other cars and trucks, you can tell if your Nissan Maxima needs a new thermostat if your engine is running hot, or if your heater is no longer blowing warm air. The good news is that it doesn't take long to change the thermostat in a Maxima, so it's a job you can likely tackle yourself.
Difficulty: Moderate
Instructions
Things You'll Need
Container
Screwdriver
10mm socket or wrench
Nissan thermostat and gasket
New coolant (if necessary)
1

Disconnect the negative cable from the battery. Loosen the radiator cap. Open the drain plug located at the bottom left of the radiator. Drain the coolant from your Nissan Maxima into a suitable container. Reuse the coolant if it's relatively new and clean.
2

Follow the upper radiator hose to where it connects to the thermostat housing at the front of the engine. Loosen the hose clamp on the engine-end of the radiator hose and pull it off the thermostat housing. In 2002 to 2006 Maximas, remove the air duct and air cleaner case for easier access.
3

Use a 10mm socket or wrench to remove the two bolts on the thermostat housing cover. Remove the cover. Note the position of the old thermostat before removing. Take out old thermostat. Scrape old gasket residue from the inside of the thermostat housing cover.
4

Insert the new thermostat into the thermostat housing, with the spring-side facing into the engine. Install the new gasket. Nissan recommends that you use a Nissan thermostat and gasket rather than parts issued by other manufacturers.
5

Replace the thermostat housing cover and tighten the bolts. Reattach the radiator hose to the thermostat housing. For 2002 to 2006 Maximas, replace the air duct and air cleaner case.
6

Refill the radiator with reserve or new coolant. Start your Maxima and allow it to run until it reaches normal operating temperature. Check for leaks where the radiator hose joins the thermostat housing and tighten the hose clamp to stop any leaks, if necessary.

Tips & Warnings

Don't drain coolant from your Maxima while the engine is hot.