How to Install a Northstar V8 Thermostatby Gregory Crews
The Northstar V-8 is an engine manufactured by General Motors and used in the Cadillac line-up. This engine is made to detect coolant problems and will shut down part of the engine and allow it to air cool if it is overheating. A faulty thermostat is one of the main reasons this engine could overheat. The thermostat is responsible for governing the coolant system and regulating coolant flow in to the engine.
Allow the car to cool down before performing maintenance. The car should be parked for at least one hour.
Open the hood for access to the engine compartment. Locate the upper radiator hose. Follow it to the engine. The radiator hose is mounted to the thermostat housing. Place a drain pan under the engine where the radiator hose stops at the housing. This will ensure no coolant leaks on the ground when taking the housing apart.
Unbolt the two bolts on the thermostat housing. Pull the housing cover off the housing and angle it toward the drain pan to catch any coolant that is leaking.
Scrape the old o-ring off the mating areas of the assembly with a razor knife. Slide the new o-ring around the piping.
Pull the old thermostat out of the housing. Replace with the new thermostat. Ensure the thermostat is deposited with the spring end in first.
Bolt the housing back together with the socket wrench. Ensure both bolts are tight so the o-ring can create a seal.
Twist the radiator cap off the radiator. Fill the radiator with pre-mixed coolant to ensure it is full. Start the car and allow it to idle until it is warm. As the level in the radiator drops, fill with additional coolant until it can not hold anymore.
Tighten the cap back on to the radiator. Turn off the engine and close the hood.
- Automedia: Thermostat Replacement
- "Cadillac Haynes Repair Manual for DeVille (1994 thru 2005), Seville (1992 thru 2004), and DTS (2006 thru 2010)"; John Haynes; 2010
- The thermsotat and o-ring can usually be purchased as a kit at the local automotive parts store.
Things You'll Need
- Socket wrench
- Socket set
- Razor blade
- 1 gallon pre-mixed coolant
- Use caution disposing of waste coolant. Contact a local recycling center for the proper disposal method.
Gregory Crews has been in the film industry for three years and has appeared in more than 38 major motion pictures and 16 television shows. He also writes detailed automotive tutorials. His expertise in the automotive industry has given him the skills to write detailed technical instructional articles.