I posted once before about this problem, but I have new info now.

When starting after sitting for 4+ hours, my car makes a loud moaning noise that appears to come from the alternator area. The noise is not present at idle, just at 1200-1600 rpm. The noise goes away in approx. one minute when driving. If you let the car idle long enough (couple of minutes), you will NOT have the noise when you drive-away. The noise is worse when its cold. I have replaced the serp. belt, tensioner and both idlers. The PS pump and alternator turn smoothly, with no gritty feeling when they are turned. The car Never makes the noise after it goes away unless it is left to sit for several hours.

Could the water pump be making the sound?

I replaced the PS fluid with synthetic, could this be the cause?

Help!!

Synthetic fluid will not cause the noise.

Use a broom handle, very long screwdriver, or a nice straight stick as a stethescope; place it on the bone by your ear and the other end on the non moving parts - AC, PS, Alt. Be careful not to touch the belt. Obviously, when the noise is present...

Don't forget to look at the other side, like tranny pump. If that is making noise check the ATF level.

Klaus
--
There is no present time, just the past and future

Klaus: I bought a stethescope, but the noise cannot be pinpointed. The noise sounds like the belt is slipping, but it isn't. I can even feel a vibration in the radiator cowl when the noise is occuring (not the electric fan). At the end of the noise-period, after about 45-60 seconds, the sound raises in pitch and diminshes until gone. Like a something rotating that finally "hooks-up".
PS has been bled, and turning the steering wheel during the noise does not affect the noise (and the PS works fine). Changing the alternator load likewise does not affect the noise.

I am really stumped by this!!

when I read your : strange noise at startup I knew it had to be the same I hear in my 1996 850.Thorough searching has not provided an answer. T-5 engine of course.

....figures!

Has it got worse?

Is the A/C compressor trying to engage with a slipping clutch (as in Defrost turned ON)?

Nope. Same noise whether ac on or off.

Thanks.