Strange Metallic Whirring Noise

magnumdart said

Almost sounds like a couple keys jangling together. If there is nothing under the dash rattling around, and the pipes aren't banging around against the hangers or something then I would spray a little water on the belts and pulleys and such. If that doesn't quiet it down then it would be time for a stethoscope.

Also, there is a short period where it sounds like there could be some piston slap going on, but that isn't the noise your talking about.

Alternators have been known to make those strange erratic noises also.

I had a water pump damaged in a car/deer altercation with just enough damage to cause it to squeak for 40,000 miles before I finally tired of the noise and changed it out.

I know you seem to think the sound originates from the rear, but sound is a wave and the fan can blow it around, other sounds can interfere, and an engine compartment is like a tin can so it will echo all over the place.

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The key jangling sound is from one of the Ultra Flo mufflers. Something has been loose in there for a while. The video isn’t too great. I will see if I can improve on that later today by crawling underneath the car. I am absolutely positive the noise is coming from the rear half of the engine. Definitely have tried pulling belts one at a time, with no change. Nothing under dash rattling; the noise is much more audible outside. Alternator was replaced recently, which had no effect on the noise. Water pump replaced at same time.

I tried swapping distributors (checking for advance spring noise on the old and new one first) this morning, but that had no effect. Drove the car to work this morning again, which is 30 miles one way, mostly highway. Ran fine, no misses, coolant temp great. Same deal with noise though. Fired the car up, was quiet for a bit, then starts making the noise as soon as I pull out of the garage. Keep on my way to work, stop at light and idles for a moment and it goes away. Give it some gas, or begin moving, the noise becomes audible again shortly thereafter and there again at the next light. This has been the scenario for many months/miles it seems.

Thank you all for chiming in on this. Frustrating as hell to me, since I hate uncommon noises like this, or any issues present whatsoever. Sure I can disassemble things in the engine to really see what’s going on, but I am just not completely sold on needing to do that based on the symptoms described.