Where is the thermostat located on a GMC?
Remove the thermostat from the engine by following the upper radiator hose to where it meets the thermostat housing. The thermostat housing is where the opposite end of the upper radiator hose mounts to the engine.
Do you have to drain radiator to change thermostat?
With a normal top-mounted thermostat you need drain only part of the cooling system . Do not drain it while the engine is hot — you may be scalded. Drain the coolant from the radiator tap, or from the bottom hose, until it is below the level of the thermostat housing.
What do I need to replace my GMC Sierra thermostat?
Because this guide focuses on replacing your Sierra thermostat, if you are still having overheating problems, check our guide on overheating GEN III engines, and how to troubleshoot overheating. To replace your 4.8 liter Sierra thermostat, you’ll need coolant as well as a 10mm socket and wrench.
How do you install a new thermostat in a car?
Prepare the new thermostat by inserting into your old thermostat housing, and apply a thin layer of hi-temp gasket maker. Carefully push the new thermostat and radiator hose / thermostat housing back into the engine. Be careful aligning the thermostat housing, and when fully installed, insert the 10mm bolts and tighten to specification.
Why does my GMC Sierra thermostat Read Hot?
There’s a wax thermal pellet incorporated inside your GM thermostat, and if that’s stuck closed the lower radiator hose will remain cool, even though your temperature meter reads hot. Because this guide is working on hot components and near your exhaust and cooling fan, if you are not comfortable working on your own vehicle, stop now.
What is the thermostat part number on a Sierra?
The part number for the factory thermostat for your Sierra is GM part number 12562740, 12571261, or 12562740. The temperature rating for these thermostats is 186 degrees, and that is the stock rating for your Sierra.