How to Replace Thermostat
Learn how to replace thermostat with our detailed step-by-step guide. Follow our easy instructions to get it done right.
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0 of 6 steps completedStep-by-Step Instructions
1 Step 1: Diagnose Faulty Thermostat
Step 1: Diagnose Faulty Thermostat
Check for engine overheating, poor heater performance, or thermostat stuck open/closed.
Infrared Thermometer
Non-contact temp gun for testing thermostat operation
2 Step 2: Drain Coolant Below Thermostat Level
Step 2: Drain Coolant Below Thermostat Level
Open radiator drain cock or remove lower hose to drain coolant below thermostat housing.
Oil Drain Pan
Large pan for catching drained coolant
3 Step 3: Locate and Access Thermostat Housing
Step 3: Locate and Access Thermostat Housing
Find thermostat (usually where upper radiator hose connects to engine), remove any obstructions.
4 Step 4: Remove Housing Bolts and Old Thermostat
Step 4: Remove Housing Bolts and Old Thermostat
Unbolt thermostat housing, lift off, remove old thermostat and gasket, clean mating surfaces.
Socket and Ratchet Set
Tools for removing thermostat housing bolts
Gasket Scraper
Tool for removing old gasket material
5 Step 5: Install New Thermostat and Gasket
Step 5: Install New Thermostat and Gasket
Install new thermostat in correct orientation, apply new gasket or RTV sealant, reinstall housing.
Engine Thermostat
Replacement thermostat for your vehicle
Thermostat Gasket
Housing gasket or O-ring seal
6 Step 6: Refill Coolant and Bleed Air
Step 6: Refill Coolant and Bleed Air
Refill with 50/50 coolant mix, run engine, bleed air from system, check for leaks.
Engine Coolant 50/50
Pre-mixed antifreeze for refilling (1 gallon)