I have a 2002 V6 with about 80,000 miles. Just replaced the alternator 6 months ago, had an ignition system problem about a year and a half ago. I was driving home from school for the weekend (about 200 miles) just today. After 100 miles, I pulled off the freeway and parked for 20 minutes. Started it up again, only to hear a loud whining noise that changed with engine speed. It sounded like the water pump. It also started misfiring. I didn't take any chances, had it towed all the way home so I couldn't really diagnose anything yet.

The whining is definitely coming from the engine. I thought it was the water pump when I heard it, but I didn't think the pump could cause a misfire. No indication of any problems before this. Any ideas?

 

Pull the belt off and you can start it and see if the whining is still there or spin the pulleys to see if you can isolate it.

 

I'd bet water or power steering pump.

 

Found the problem. Seems like there were a couple things going on. The bearing in my idler pulley was bad, so part of the noise was coming from that. But th main noise is coming from the camshaft synchronizer. I pulled off the belt just as suggested and the noise was still there, so I took out the cam sensor and synchro and ran it for a couple seconds. No more noise, no more misfire. When I called the parts department at the Ford dealer the guy I was talking to knew exactly what my car was doing once I told him what part I needed, so it must be a pretty common problem