Preparation:
- Gather the necessary tools and parts, including a new thermostat (OEM or high-quality aftermarket), a new thermostat gasket (if needed), coolant (check your owner's manual for the correct type), a funnel, a catch pan or bucket, and a set of basic hand tools.
- Make sure the engine is cool to the touch. If it's recently been running, allow it to cool down completely to avoid burns.
Procedure:
1. Locate the thermostat housing:
- The thermostat housing is usually located on the front or side of the engine, near the upper radiator hose.
2. Drain the coolant:
- Place a catch pan or bucket under the radiator drain plug (usually located at the bottom of the radiator).
- Open the radiator drain plug to allow the coolant to drain.
3. Remove the old thermostat:
- Once most of the coolant has drained, remove the bolts or clamps holding the thermostat housing in place.
- Carefully remove the old thermostat and discard it.
4. Clean the thermostat housing:
- Inspect the thermostat housing for any debris or rust.
- If needed, clean the housing with a wire brush and a degreaser or solvent.
5. Install the new thermostat:
- Before installing the new thermostat, make sure the gasket surface is clean and smooth. If needed, apply a thin layer of sealant to the gasket surface of the thermostat housing.
- Position the new thermostat in the housing and make sure it's properly seated.
- Replace the thermostat housing and secure it with the bolts or clamps you removed earlier.
6. Refill the coolant:
- Once the thermostat is installed, use a funnel to refill the coolant system through the radiator cap or expansion tank.
- Refill the coolant to the recommended level specified in your owner's manual.
7. Check for leaks:
- Start the engine and let it run for a few minutes.
- Keep an eye out for any leaks around the thermostat housing or the radiator. If you see any leaks, tighten the bolts or clamps as needed.
8. Test the thermostat:
- Once you're sure there are no leaks, take your car for a test drive.
- Monitor the temperature gauge on the dashboard. If the engine temperature stays within the normal range, the thermostat is working properly.
Remember, the specific steps and details may vary slightly based on your exact Altima model and engine type. If you're unsure about any part of the process, consult a Haynes or Chilton repair manual or seek assistance from a qualified mechanic.
