Chirping sound 2002 explorer

[northside]

Well I had that awful sounding 'chirping' sound' that was driving me crazy. I was unable to find a solution for it. I changed my belt, tensioner, and idle pulley to no avail so I gave in and went to FORD and paid for a diagnostic. Lucky for me the noise at the time was real loud and as a result, the chirp turned out to be bad alternator bearings. I went and bought a new alternator and belt, replaced it myself and the noise was gone. Now I have to deal with a second noise which sounds like at startup a whining sound maybe a vaccum leak?

 

[northside]

02 explorer xls 2wd 4.0
I spoke too soon, after 2 wks of no chirping sound now its coming back after startup. Once the engine warms up the sound goes away for the rest of the day. When i took the belt off and ran the engine there was no noise whatsoever so do you think its an external part thats bad. Its not the timing belt. Alt, tensioner, idle pulley, belt changed. That leaves the PS pump and A/C compressor to be checked. Anyone that got their noise to stop please let me know.

 

[fusseli]

I have a chirp as the a/c clutch engages/disengages. Any chance your a/c was running during your tests?

 

[northside]

No my a/c was off.

 

[mwant0276]

is that startup sound the intake? intake usually makes a sucking sound when the engine is cold

 

[Cdaddy78]

Also leaves the water pump, which was my problem. I initially took it to the stealership for them to fix the squeak, but when they pulled the car around to return it to me, it was chirping away. Decided to just fix it myself. When you take off the belt you can spin each pulley by hand, and if not hear, at least feel bad bearings.