have a 3.9L mustang which has started squealing upon starting the engine, sounding like a belt , but once the engine warms up, the squeal goes away. i replaced the belt, idler pulley, tension pulley, water pump and alternator but still had the squeal. i took belt off and started engine to see if just maybe it was none of the remaining and it still squeals without the belt on. it has now started giving engine light and the code came up cam posistion sensor which i replaced and cleared code, now its giving same code again. can someone offer a suggestion what else i can do to find the squeal and stop my money pit from draining me??

 

As far as the sensor going out I can't tell you but I know with the belt I had mine doing the same thing would not stop until I switched the belt to a Goodyear Gatorback it stopped and never came back. I got my from Advanced Auto for like 30 bucks.

 

If you took all the belts OFF and the car still squealed when started cold.. geez it must be something to do with the timing chain(?) have you checked/changed the oil often? Have you gone a long time with VERY LOW oil level?

 

Oh missed that part. Ya sounds like timing chain then if you have a squeal still going and your CPS is going out.