Another "Funky Engine Noise" thread
 

https://www.youtube.com/watch?v=RuBu...ature=youtu.be

Just passing through, but I thought maybe I could take advantage of the collective experience that is the Mazda Forum.

What we have here is a 98 Mazda Protege with 160,000 on the clock. I just drove down to San Diego from southern Oregon for the holidays. I left on a fresh oil change and filter, using high mileage Valvoline oil. Checked tires, brakes, fluids, linkages, everything before I left. It ran like a top on the 20 hour drive with no complaints. I checked the oil at every fuel stop and kept it topped off. And now, I have this noise.

It stumps me. It doesn't seem to be RPM dependent, though it is more consistent at certain RPMS. 2,000, for example. I've since done another oil change into a clean pan, and found only the faintest of metal filings, which I would expect from an engine this experienced. The oil looked good. I had a mechanic give it a listen and suggest the water pump could be the cause, at it didn't seem to be bottom end noise. I popped the belt off the water pump and ran it. It still clattered. The video is with the waterpump and power steering pump DISABLED. There's no obvious vibrating parts and the engine mounts looks good. I'm stumped.

Any suggestions would be appreciated. I'm handy with a wrench and need to get north.

Hard to say without my hands on it but it could be the timing belt tensioner spring broke and allowing the tensioner to flop or the idler/tensioner bearings worn out. If you can get something long that you can put against your ear and place the other end at various locations on the timing cover you might be able to isolate it. It is also not very time consuming to remove the upper timing cover to see whats going on.Remove the valve cover then reinstall it after you get the upper cover off. Look closely at the pulley on the crankshaft for wobbling also.