GM 12706567
Thermostat Housing

Start by partially draining the cooling system through the cooling system draining and filling (GE 47716) procedure when replacing the engine coolant Thermostat (LY7, LLT). After removing the upper Intake Manifold and disconnecting the surge tank outlet pipe from the Thermostat focus on the radiator surge tank outlet hose/pipe replacement (LLT) procedures. Remove the Thermostat's three hardware components starting with the coolant pipe/Thermostat housing bolt then the coolant pipe upper bolt and finally the coolant inlet pipe. To remove the Thermostat you must first remove the Thermostat bolts before discarding the Thermostat seal. Fasten the new Thermostat by applying new Thermostat seal then tighten the Thermostat bolts to a torque of 10 n.m (89 lb in). Verna with a new seal along with fasteners (2 and 7) to reinstall the coolant pipe before you connect the surge tank outlet pipe to the Thermostat and install the upper Intake Manifold. Complete cooling system filling based on the cooling system draining and filling (GE 47716) procedure.

Remove some fluid from the cooling system as a first step to replace the Thermostat Housing on ly7 or llt (3.6L) engines through approved draining procedures. When replacing the Throttle Body on the llt engine you must remove it first. To proceed with the replacement start by removing the Thermostat Housing bolts after disconnecting the Radiator Hose from the thermostat. Thoroughly wipe the Thermostat Housing sealing surfaces while discarding both old seals before installation. Reposition the thermostat onto its housing after installing fresh seals into the Thermostat Housing. Close the thermostat with new bolts and secure them using torque settings reaching 10 nm (89 lb in). After installing the new thermostat, reattach its Radiator Hose to the outlet while the Throttle Body replacement becomes necessary for llt models. Another step of cooling system completion involves filling up its components.

Disconnecting the heater hoses that are connected to the heater core is the first step while replacing the engine coolant Thermostat Housing (LY7). As for the Thermostat, remove and the bolts of the Thermostat Housing then remove the Thermostat Housing with the heater pipes, hoses and bolts. Clean the sealing surfaces meticulously with a tool such as gasket remover (J 28410) made of plastic gasket scraper, or the like. Next take the heater pipes and hoses and attach them to the Thermostat Housing, put a new gasket and loosely fasten Thermostat Housing bolts to hold the gasket. For the Thermostat Housing and heater pipes, heater hoses, gasket and fasteners, make sure to attach them as well as use the correct hardware and use hardware stocks like bolts, screws, and keep the fasteners in the right order like for replacement, hardware needs to be in the right specific part number for the application. Do not apply paints, lubricants or corrosion inhibitors on the fasteners and joint surfaces as it can affect torque and clamping force. Follow the right tightening sequence and specifications, tightening the Thermostat Housing to 20nm(15 lb ft). Lastly, mount the Thermostat and reconnect the heater hoses to the heater core.

Your first step when replacing the engine coolant Thermostat (LY7) should include partial draining of the cooling system. Proper maintenance requires that engine intake manifolds stay connected during the work. The required procedure requires removing both the upper Intake Manifold while also removing the lower Intake Manifold. Workers need to disconnect the surge tank hose from the Thermostat before removing the coolant pipe/Thermostat housing bolt and the coolant pipe upper bolt. The coolant inlet pipe needs to be disconnected from the Thermostat before the Thermostat bolts get removed. Remove the Thermostat from its position then dispose of the old Thermostat seal. To install the new Thermostat keep it together with a new Thermostat seal while using the correct fasteners at their proper locations otherwise damage may happen. Install the bolts on the Thermostat at 10 nm torque setting (89 lb in). Install the coolant pipe back in place using its new seal and fasteners (2 and 7), followed by reattaching the surge tank hose to the Thermostat. Place the upper Intake Manifold with the lower Intake Manifold while filling the cooling system.

The process begins with disconnecting heater hoses from the Heater Core when replacing the engine coolant Thermostat Housing (LY7 - Gas, 6 CYL, 3.6L, SFI, V6, Alum). Use the gasket remover (J 28410) to methodically clean both sealing surfaces. First remove the Thermostat and its housing bolts followed by removing the Thermostat Housing together with heater pipes and hoses and bolts. Connect heater pipes together with hoses to the new Thermostat Housing followed by a fresh gasket installation and a partial bolt installation to retain the gasket placement. You should first mount the Thermostat Housing alongside heater pipes and hoses and gasket before tightening the Thermostat Housing bolts to 20 n.m (15 lb ft). Cut the end of the heater hoses before installing the Thermostat unit and wrapping the hoses around the Heater Core.

Remove the upper intake manifold as outlined in the Intake Manifold Replacement (SFI) instructions.

Detach the radiator hose from the water outlet and remove the water outlet housing bolts.

Remove the thermostat and the thermostat housing bolts, then take out the thermostat housing along with the heater pipes, hoses, and bolts.

Place the NEW seal onto the thermostat housing.

Remove the thermostat bolts and take out the thermostat, discarding the thermostat seal.

Clean the sealing surfaces of the thermostat housing and water housing.

Install the water outlet bolts and tighten them to 10 N.m (89 lb in).

Remove the intake manifold inlet duct and clamp, surge tank inlet hose fitting, heater inlet hose fitting, and EVAP canister purge solenoid valve.

Install the thermostat housing with the heater pipes, hoses, gasket, and bolts, ensuring to tighten the thermostat housing bolts to 20 Nm (15 lb ft).

Reinstall the coolant pipe with a new seal and fasteners, then reconnect the surge tank hose to the thermostat.

Partially install the thermostat housing bolts to retain the gasket.

Install the thermostat into the thermostat housing.

Reconnect the heater hose and radiator hose to the thermostat housing, reinstall the air cleaner outlet duct, and fill the cooling system.

Assemble the heater pipes and hoses to the thermostat housing, install a new gasket, and partially install the thermostat housing bolts to retain the gasket.

Loosen the intake manifold duct clamp.

Remove the thermostat bolts and then remove the thermostat, discarding the thermostat seal.

Begin by partially draining the cooling system.

Fill the cooling system using the GE 47716 -Vac N Fill Coolant Refill Tool or the Static Fill method.