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I posted a while back, thought i had it pinpointed with the power-steering pump, but that didn't end up being an accurate diagnosis. 97civic mt, 109,xxx. all fluid levels are normal.

Immediately after oil change (pure 1 filter castrol gtx) transmission drain/refill (mt honda fluid) and new plugs (ngk) there is a metallic whine/wrrr / Howl that is directly affected by engine rpm. On first start, noise was very loud, audible to maybe 50'. it has been quieter since, audible to maybe 5-10'. its most noticeable at 1600 rpm and again at 1900rpm for what its worth.

temp gauge indicates normal, no CEL. engine idles fine, shifts normal.

I've only driven about 15miles since the oil change. I cant figure out exactly where it is coming from. I am leaning towards somewhere near the bottom of the car but that could just be it echoing off the ground and seeming louder.

no oil leak, coolant leak that i noticed. no smell of burning rubber (loose belt)
everything seems normal with exception of new noise.

what would a bad water pump sound like? bad oil pump sound? pully bearing of some sort failing sound?

I dont know if AC works, its cold out so it blows cold air regardless.

 
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anything?

I still cant isolate the noise. It sounds alot more like a howl, than previously described. tone is similar to fingernails on a blackboard, but continuous without any pause.

a couple ideas from random google searches:

exhaust manifold. I dont know how it would make a consistent noise though as opposed to intermittent noises due to vibration. in my mind i cant see how that would be it.

Cooling fan clutch... do we have one? electric motor on rad fan...

input shaft bearing/throwout bearing- no change in noise with application of clutch pedal

still unable to remove a/c and alternator belts. bolts and tension pulley wheel are unable to be removed

transmission fluid/oil/ps fluid all normal levels and freshly changed with honda fluids.

NEED HELP!

 
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This is how to diagnose it.....INPUT SHAFT BEARING
-Start your car.
-Roll up the windows, turn the radio off, and turn the blower motor for the AC/heater off.
-put the car into neutral, and take your foot off the clutch pedal
---- if you hear the noise now, it is the INPUT SHAFT BEARING. if you press in the clutch, the noise should go away.

 
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[QUOTE
input shaft bearing/throwout bearing- no change in noise with application of clutch pedal[/QUOTE]

I may have worded it it poorly. its not input shaft bearing.. the noise was there regardless of clutch position.

I ended up cutting off the old belts to get better access at moving things around. Its been a somewhat intermittent problem lately, but with all belts off, there was no noise. new belts are installed and i heard it just 1 time since then. I'm pretty content thinking its one of the pulley wheels. All the bolts for tensioners and pivots are anti seized now so if it comes back i wont have as much of an issue removing belts to isolate which one is the culprit.