A couple of days ago one of the heating fans buried in the dashboard started making an ungodly noise: it's low-pitched and becomes louder/quieter as the fan is run quicker/slower. Without wishing to "jinx" the situation, everything is working well - it's as if something has got into the system and is in the airflow causing the noise.

I'm looking for advice to diagnose the problem in the first instance. Any ideas? Has anyone had a similar problem?

 

A piece of the insulation for the blend on the fan motor case on either one or both assembly is stuck in the squirrel cage. You can fish it out with a bent coat hanger through the open recirc door when you see it in the cage. There have been many topics on this but old car, old threads. Youll have to search for more info and pics.