I turned on my heater this morning on my way to work and it made a sound like gravel being tossed around in a plastic container. It was wierd. I cant think of what it is. I just got back from Oregon and the bugs(midges) were really bad, they could have gotten into the vents. But it was too loud to be those little bugs. I dont know much about the air system so Im asking you guys. Any suggestions? Thanks

 

Watch your tempertature gauge and look for coolant leaks. That gravely-grinding sound is likely your water pump failing.

Ed

 

Really? I just had the water pump replaced about 8k miles ago. Why would that sound be related to my H2o pump? I was thinking more heater core or something like that....

 

Found out what it was. A rat made a nest somewhere in my engine compartment, he brought about 30 or more pieces of Dog food up into the fan/dash area. So every now and then pieces of dog food fall out from underneath the dash. It stinks too!! And I cant turn my heater on or it vibrates the entire dash. I cant seem to get it all out. SO I guess I have to tear into the dash. Dang rats!!! Anyways, just thought Id post it.