I am hopefully just fearing the worst...but my car, belt on/off is making a very loud squealing metallic noise from down at the bottom of the motor, behind the crank pulley. It sounds external to me but not sure.

About 2 months ago, I started to notice the noise. I had a harmonic balancer go out in a Crown Vic a few years ago, the noise was almost exactly the same, so I figured that must be the issue. I replaced it with what ended up being a pretty crap Chinesium aftermarket one, which made the noise stay the same, and introduce a vibration. Replaced that with a used OEM one, which resulted in the car running as normal, but the noise is still present. It doesn't seem to be getting any louder, or worse sounding, but it has become a constant noise once the engine is warmed up, where as when it started it was more random it would do it.

Oil pressure is still excellent. 60-70 cold at idle, 40-55 hot at idle. Car runs perfectly fine, still has normal power, and isn't consuming anymore oil than it ever did in the past few years ~(1 qt. or so every 3k) 140k miles.

The front main seal wasn't leaking, everything "looked" normal behind the crank pulley, and looking in the inspection cover, the rear main doesn't appear to be leaking either. Engine still runs smoothly. The noise is still the same now as when I started, so I don't think it is a result of me not properly installing the pulley.

I plan to send it to the dealer this week, that i somewhat trust, but any advice or help here is greatly appreciated.

Thanks.

Maybe record it for us.

Could be a bad timing chain tensioner. A spun bearing wouldn't survive months of driving without seizing up (unless it has been parked for months). I would also like to hear a recording of it.

How many miles has it been making this sound?