Rattling noise,and think it is the pully on the altenator 2001

check the altenator for bad bearings , also check the idler pully bearings

Check all of your belts and pullies. Sometimes it helps to remove the belts and turn the pullies by hand. Also run the engine without the belts for a few seconds. If the noise is still there, then it is most likely timing components rattling.

Hi Julie,

If your belt only "screeches" when you first start your engine, the problem is most likely to be related to either your alternator or your air conditioner. Sometimes the bearings in these things start getting worn and cause excess resistance to rotation and will cause a screaching noise that goes away once they are moving. This usually also causes "glazing" on the belt.

Look at the ribbed side of the belt. If it looks "shiny" rather than just a dull black, this is glazing. It may not be necessary at this time to replace anything like the alternator or the air conditioning compressor, but I would recommend replacing a glazed belt and do a THOROUGH check of your pully assemblies while you have the belt off.
Spin all of the pullies (including the tensioner and idler pullies) by hand with the belt off. You should not be able to "hear" them spinning. Any pully or component that feels rough or has a rough or rattling sound when you spin it by hand should probably be replaced.

if it does not comingand from the engine check all the belts and altenator pully, air compresor pully,power steling

So you found the problem

Now check all the tension and idler
belt pullies

disconnect the negative battery. remove the belt by rotate the tensioner roller clockwise. from the left car side u will see three hexagon screw 13mm under the altenator. loose out the screw and remove the altenator. before that unplug the two wire behind the altenator.tq

The best way to find the noise is to remove the belt
and check each pully by hand. If a pully locks up it
will make more of a screeching sound. A rattle sound makes me think your idler pully is loose.
Hope this helps. Good luck.

No the pulley grooves are a sleeve around the crank. this sleeve will break loose.

when you put a new belt its ok for a while and its come back if all our problem started when alternator was change if everything is straith got the right poolly on it right amounth of groove. the poolly is worn off the belt seat to deap in the groov e it hapen with rebuilt alternator check it out pierre

This is because of the problem with the clutch. So you better consult a technician to fix it up