I have 97 4.6l, elec fan (clutch fan gone). I get an intermittant rattling from the front part of my engine, changed out timing belt and tensioners 2 years ago. The sound comes and goes and seems to sometimes increase/speed-up when gas is applied, sometimes it stops. It sounds like it might be a water-pump bearing (?) How easy is it to swap out waterpumps? Haynes makes it look easy, just want to know if that is the case, if I should check some other stuff, or anything to look for? Thanks

 

I would start by removing drive belt and running engine,but DO NOT run more than couple minutes. This will let you know if it is something belt driven or internal engine. Then since you have belt off you can spin and check all belt driven components. If it is the water pump, they are pretty easy to change.

 

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