The thermostat you're probably thinking about is for the engine's cooling system. It's located in the engine's water pump housing and controls the flow of coolant to regulate engine temperature. Replacing this thermostat is a mechanical task, and not something you should undertake without some mechanical aptitude and the right tools.
Here's what's involved in replacing the engine's thermostat:
1. Safety First: Disconnect the negative battery terminal before starting any work on the cooling system. Allow the engine to cool completely before proceeding. Coolant is hot and under pressure, and burns are a very real risk.
2. Gather Tools and Materials: You'll need a new thermostat (the correct one for your 5.0L engine – get it from a parts store specifying the year and model), coolant (the correct type for your system – check your owner's manual or a parts store), a socket wrench set, pliers, a flat-head screwdriver (possibly), possibly a funnel for refilling coolant, and rags or shop towels. You might also need a torque wrench for tightening bolts to the manufacturer's specifications.
3. Drain Coolant: Carefully drain the engine coolant. There's usually a drain plug at the bottom of the radiator. Have a large container ready to catch the coolant. Be prepared for it to be hot, even after the engine has cooled.
4. Access the Thermostat Housing: Locate the thermostat housing on the engine. This is typically where the upper radiator hose connects to the engine. You'll need to loosen or remove the upper radiator hose clamp(s) and possibly some other components depending on the specific engine layout to gain access.
5. Remove the Thermostat Housing: Remove the bolts securing the thermostat housing. Be careful – this might require a bit of finesse to avoid damaging anything.
6. Replace the Thermostat: Carefully remove the old thermostat. Inspect the housing for any damage or debris. Install the new thermostat, ensuring it's oriented correctly (usually there's a small notch or marking).
7. Reassemble: Reinstall the thermostat housing and tighten the bolts to the manufacturer's specifications (consult a repair manual). Reconnect the upper radiator hose and clamp(s).
8. Refill Coolant: Carefully refill the cooling system with the correct coolant, following the manufacturer's instructions. This might involve using a funnel and squeezing the upper radiator hose to help remove air pockets.
9. Check for Leaks: Start the engine and let it run for a while to check for any leaks. Monitor the temperature gauge.
Important Considerations:
* Repair Manual: A factory service manual for your 1987 Pontiac Trans Am 5.0L is highly recommended. It will provide detailed instructions and diagrams specific to your vehicle.
* Mechanical Aptitude: This is not a beginner-level job. If you're not comfortable working on engines, it's best to have a qualified mechanic do the work. Improper installation can lead to engine damage.
* Coolant Disposal: Dispose of the old coolant properly. It's toxic and should not be dumped down the drain or onto the ground. Check with your local waste disposal authority for proper procedures.
In short, there is no "thermostat" to install in the dashboard. The engine's thermostat is a vital part of the cooling system and requires careful replacement by someone with mechanical experience. Don't attempt this unless you're comfortable with automotive repair, or consult a qualified mechanic.
