>> Stay informed about: Tip on thermostat removal on 3.4l Alero
Remove the air filter cover and air filter.
Remove the air ducts, Mass Air Flow assembly (no need to remove the
Remove one end of the heater cross over pipe (the end with the bleeder
Remove the surge line from the thermostat housing pipe. (use a 15mm and
1/2 inch open end wrenches. Yeah, why not use an 11mm nut?) If nut is
rusted or siezed, you may have to cut the metal surge line with a pipe
cutter and use a short rubber hose and clamps to connet the pipe during
Remove the two rubber hoses from the heater pipe line going to the
Remove the rubber hose on the right hand side under the intake manifold
No need to remove the heater pipe line from the rubber hose going the
the heater core. There should be enough play on the heater pipe to get
it out of the way
Using a 13 mm 1/4 inch drive socket wrench, remove the upper left hand
side thermostat housing bolt
Using a long handle 13 mm close end wrench, loosen (do no remove) the
lower right hand side bolt of the thermostat housing. This side is open
ended and will slide out of the bolt.
No need to remove the heater rubber hose from the thermostat housing
pipe. There is enough play to wiggle and pull the pipe to get to the
Reverse of the Removal steps.