buicklesabre00

before the water pump was replaced there were few occasions this situation would occur (6 month - 10,000 miles)

maybe about 10 times and would say 4/10 was within a month less to its replacement

situation: would start car, drive some way (10-300 miles) without any bad noise , then come to a stop then a whirring sound would appear on the passenger right side
and then continue whirring upon acceleration with a slight knock sometimes at certain shift points , above 30mph sound not audible .
if quickly accelerated the knock would not appear, just the whirring.

would turn car off , wait a couple minutes, start car and it would go away



got the water pump(acdelco oem) replaced and after one thousand miles the sound had re-appeared after one hour of good driving.
then took it for a half hour drive without any bad noise then once again come to a stop and the whirring sound reappeared, whirring but also at one point a sound kinda rubbing grinding, -
came home , parked car, engine on, dont hear it


coolan level in reservoir is same, a slight wetness near thermostat housing , no overheating , dunno if its droping at the weep
steering wheel moves freely, no screeching



have i just gotten bad bearings on this new water pump ?

could it be some thing else that occurs inconsistent and makes a whirring noise and a slight knock at different points in acceleration and not audible at around 30mph?

pretty common 3800 issue is a/c compressor clutch noise, see if it goes on and off with the a/c or defrost

I'm with Justin. Sounds like your A/C compressor is making some noise.

You might also want to check every point that your serpentine belt goes on. like alternator, and the A/C compressor as mentioned, power steering and especially the idler pullies. look at the serpentine belt. kind of sounds like a bearing has locked up and the belt is being pulled across. then again maybe not.

the ac pulley plate does not rotate

should the ac pulley'* bearing be replaced or the ac clutch ?

it doesnt move when you turn on the a/c? make sure you are getting power to it, the pcm controls it and if a safety is bad then it wont be calling for the clutch to engage

My '00 LeSabre is also somewhat noisy on startup idle (more along the lines of constant squeaky whirring, no knocking/grinding like the OP), and I'm wondering about bearings within all those various pulleys on the serpentine belt path. How can those noises be narrowed down easily?

Scotty, there is a video on youtube called Garage Essentials 2-Mechanics Stethoscopes, check it out, I tried to link it here with out success, sorry.

2004 Bonne SLE
1971 Chevelle SS

no noise during this
ac off - plate does not rotate
ac on - plate does rotate

by safety you mean the relay ?
could just putting in a new relay stop this or is it definitely the clutch?

i thought you meant it wasent turning on. sounds fine. what do you mean no noise during this?