Dry bearing ?

[Techkiwi]

So a week or two back started hearing a high pitched "whine" from my 172 engine, finally had time to take a bit of a look and I believe the noise is most likely a dry bearing somewhere, using a mechanics stethoscope it seems to sound loudest around the inlet/outlet pulley area (there doesn't seem to be any real noise coming from the accessories belt tensioner at the top or the idler at the bottom).

I had the dephaser changed about 2 years ago (Genuine OE pulley) so could this be my exhaust pulley on the way out ? (though noise does seem louder closer to the dephaser than the exhaust).

Anyone experienced anything similar or have any tips on a way forward, guess the next thing I'll be doing is taking the cam cover off and trying to further isolate the noise anyway.

TIA.

 

[NorthloopCup]

Try the water pump mate. Take the tension off the belt and give it a spin by hand. Also check the alternator whilst you're in there.

 

[Techkiwi]

Thanks, have checked the Alternator and it seems ok, water pump was replaced with the dephaser about 24 months ago but will check it out.

 

[hipwell]

Pas pumps tend to whine on these.

Take the aux belt off and fire it up. If the noise is gone you know its something on the aux side of things.