Toyota Repair: toyota 4runner 2000, toyota 4runner 2000, loose bolt

Question
recently i have been hearing this noise in the front of my engine close to were the pulley is in front of the motor my husband said it could be the pulley itself or the water pump its a knocking sound what would you do first check the pulley or change the water pump

Answer
I never rebuild an engine without performing simple maintenance on it first. I would check the Harmonic Balancer and make sure it is tight. I have heard many a story where people have had costly engine replacement performed when the only problem was a loose bolt on the end of the Harmonic balancer. If this bolt is tight, make sure the pulley spins straight and does not wobble. Lastly I would check the water pump. Usually when a water pump goes out, it leaks first. HOWEVER, this is not always the case. Sometimes the waterpump bearing gives way and weakens. This will cause the internal impeller to knock or make contact with the interior housing. A simple neighborhood mechanic (not dealership) will check this out for you at nominal to no cost if your husband is mechanically challenged.