Toyota Repair: 2001 Rav4- random clattering in engine compartment, drive belt tensioner, engine temp

Question
Hi,

I'm having troulbe diagnosing a clattering sound coming from my '01 Rav4. The car has 237,000 miles on it but has always ran great and still does. It runs the same regardless if the noise is/ is not present. It appears to be loudest over the manifold cover and it is a clanging noise- if I had to try and describe it, it sounds like someone is banging the butt of a screwdriver against the manifold cover. It comes and goes and has no specific behavior, meaning it doesn't happen at a specific speed or RPM, it just comes and goes regardless of speed, rpm, or engine temp. Any ideas on what it is and what needs to be done to fix it? I was hoping to get another 100,000 out of her :). Thanks so much for your time! Rob

Answer
Check the drive belt tensioner, if they become weak it can create a noise that sounds like this, if necessary remove the drive belt and run the engine without it for a few minutes and see if the noise goes away, if not you would need to remove the valve cover for a close inspection of the camshafts and gears, the timing belt should also be checked as well as the water pump, all of those can cause noise.