Rattle Noise on Cold Startup, Winding Noise Varies with RPMs when Cold

[cgrady17]

Hello,

I have a 04 Mounty 4.6L V8 with 96,000 mi. and it is making a horrible rattle and scraping noise for a couple seconds immediately after a cold start. Then it will make a winding noise that gets louder and faster as RPMs increase. The winding noise goes away after the engine warms up. The serp belt seems to be in fine condition. I'll be getting a mechanic's stethoscope to try and pinpoint its location and report here. In the meantime, does anyone have any suggestions of where to look or what it could be?

Let me know if you need more information.

 

[2Trux]

My steering pump makes nasty whining noises when started cold, sound goes away within 30 sec.

 

[cgrady17]

I wouldn't be surprised if it was the Power Steering Pump. I'll have to look into that. Thank you 2Trux. Again, I'll post here if I can narrow down the location of the sound.

 

[Kiliona]

Sure sounds like an accessory belt/ accessory bearing problem. A stethoscope would be the best option to narrow it down, as you said. I got one at sears for ~10 dollars and it works great.

One way to narrow it down a bit more, turn on everything electronic you can think of to put the biggest load on the alternator, does the noise get worse? if so probably alternator (or the serpentine belt itself)

Turn steering wheel back and forth see if it gets worse, if so PS pump (again or belt, make sure belt is in good shape before you do this, I had one one time that looked perfect but a rock flew up in it and got stuck and that fubar'ed it but only in one tiny spot, enough to make a noise like you're describing)

I doubt you have your AC on this time of year, especially when you first turn your car on, but if it were summer I'd say turn that on as well and listen for the noise.

Good luck!