So I have this weird howling/resonating sound whem it is cold. Almost sounds like a bad accordion player lol. Stuck a screwdriver to various parts as a make shift stethoscope and it appeared to be coming from the alternator. So I changed the alternator with a spare I had and its still there. Once it warms up it goes away. Water pump is fairly new, so are the idler and tensioner pulleys. I did remove the pieces from the intake boot amd sealed the holes after one of them broke so maybe those resonator chambers have something to do with it.

 

Remove belt and start up cold. If noise is gone...it's probably a idler or tensioner issue (no matter how new, cheap junk nowadays) or A/C compressor bearing or clutch fan going bad. If noise still exsits, with belt removed, then l'd focus on air intake tubing from air cleaner housing to engine, cold idle solenoid hoses or vacuum hoses.

 

Check your Power steering pump? ACE pump? Air Con compressor bearing?

 

SAI pump runs when cold & they can be kinda loud.

 

^^^^^ Brilliant.

Yes, SAI can be quite loud...especially if it is going bad. Changed the 03 SAI pump after a few months of complaining from the driver.

 

My 04 SAI pump is a little louder than most because I ditched the rubber supports which do not hold up long in TX for just 3 normal bolts. Bit more vibration when it runs but I can deal with that vs an SAI pump falling off every 6 months.