It seems that noisy blower motors are a pretty common issue, so I figured we should have a how-to. I also included a pretty decent video of the procedure being done on a Cobalt, even though it is completed differently. Updates
added after I completed the repair. They should help.
Safety glasses (seriously on this one)
Flat blade screwdriver
Utility knife with new blade
Drill with 3/8" bit
8 screws (I used #8 1/2" hex head stainless sheet metal screws. This worked just fine, but #8 5/8 would have been perfect.)
Replacement Blower Motor and included service ring (approximately $75)
1. Disconnect the blower motor electrical connector. To do so, insert a flat blade screwdriver on top of the connector in the slot and push DOWN while pulling out. Pull out the rear wire holder rivet and tuck your wires away. It's difficult to control the blade in such a tight space and you don't want to slice your harness wires.
2. Remove the blower motor and cup from the lower case by cutting through the case between the circular ribs around the motor with a sharp utility knife. This is the most difficult and time consuming part. What worked best was a brand new
blade in my knife, and instead of scribing around the motor, use a "jab and push" method to cut through a little at a time. Move your blade over a little, jab and push, then repeat all the way around. Don't worry about going too deep, there's nothing to hit behind it. This method does the least collateral damage and offers the most control for safety. FYI There is an area on the front of the fan motor where there is no groove to cut. Scribe it a little, then rock the motor back and forth until it gives way. After removal, you can bring the motor to your work bench.
Cut through the case as straight as possible because the motor cup must be reused.
3. Drill out the lower blower motor cover heat stakes (1) with your 3/8" drill bit. You only need to drill about 1/4" to get through those, but going a little deeper won't hurt anything.
4. Remove the blower motor cover.
5. Remove the 2 blower motor nuts that secure it in the cup.
6. The manual says to release the blower motor retaining tab to remove the motor from the cup. I pulled up and it came out just fine.
Note: to reduce the risk of noise from vibration/rubbing, I recommend sanding smooth the plastic edges where you cut, both on the motor cup and in the HVAC housing in your car.
1. Install the blower motor (1) into the motor cup (2) that was cut out of the lower case. Check to make sure the fan blade rotates freely in the housing. Mine rubbed, so I had to shave down the plastic tabs on the cup a little to give it clearance. This was not ideal, because that's where your service ring screws go into. I didn't have a choice, so whatever.
2. Install the blower motor nuts (3). Tighten the nuts to 2.4 N.m (21 lb in).
3. Install the lower blower motor cover.
4. Secure the lower blower motor cover with 2 of your #8 1/2" screws. There are pre-fab holes in the motor cup for this already. Tighten to 1.8 N.m (15 lb in).
5. Attach the service ring (4) to the motor cup (2) with 3 of the #8 1/2" screws (5). There are pre-fab holes in the motor cup for this already. Tighten the screws to 1.8 N.m (15 lb in).
6. Go back out to your car and install the blower motor and service ring into the HVAC module using 3 of your #8 1/2"screws (5). There are pre-fab holes in your HVAC module that line up with the service ring. Make certain the blower motor electrical connector opening is facing the passenger seat. Tighten the screws to 1.8 N.m (15 lb in).
7. Connect the blower motor electrical connector.
How-To Video by 1A Auto
How To Install Replace AC Heater Fan Blower Motor Chevy Cobalt Pontiac G5 05-10 1AAuto.com - YouTube