So, a month to so ago, my heater started making a noise: not so bad on low, but quite loud on high. Definitely louder and more of a problem the faster the motor is going-- but heat and a/c still work. In the past week, however, there is most definitely a dead animal smell coming from the vents-- only really bad when the car is on. Help? Suggestions?

The only help is to dismantle the whole dash to get into the vents and remove the corpse and disinfect everything. Also get under the cowl inlet area.

I'm handy enough but no mechanic. Is this something the average person can do with a bit of patience and a median level of intellect?

It would help to know the year and model of the car. You can always start with removing the blower motor and poking around with a flashlight and inspection mirror.

Oh yeah, it's a 2003 forester, and the sound and smell seems to be concentrated behind the glove box.

Remove the glove box. That will provide access to both the blower motor and to the resistor pack. By removing both, you will have access to the intake path, and a good view of the evaporator core. Hopefully that will be enough to identify and correct the problem. By the way, shouldn't a '03 model have a HVAC filter? If there is one installed, just pull it out, and you'll find your answer.

Edited June 30, 201312 yr by avk

Yeah, that sounds like a mouse got sucked onto the blower motor. Ouch, and ewwww.

Ewwww have fun with that one.

diagrams and information regarding removal available here: http://jdmfsm.info/Auto/Japan/Subaru/Forester/2003/

 

taking the glove box out will make things much easier to access.