I am hoping you guys could help. I have a 2004 automatic, V6 mustang. My engine began squeaking a few months ago and it generally happens at lower RPMS/idle but could chirp at higher RPM's occasionally. I replaced the belt, tensioner pulley and idler pulley and the same noise exists.

With the belt off (should have just done this first)...the noise is still there. It sounds like it could be coming from somewhere around the crank pulley. I sprayed WD-40 behind the crank pulley in a desperate attempt to quiet the pulley with no result. Any idea what could be causing the noise? No other pulleys would rotate with the belt off correct?

 

Do you have a manual or automatic transmission?

 

Automatic transmission