I've have had this humming, buzzing, whisling-like sound from the front of my engine for a full season now. It follows the revs and can only be heard from inside the cabin with the firewall engine cover on. With the cover of I just can't hear and locate it. Not very laud but quite annouing.
The sound comes on as the engine heats up, at first very quiet and then grows in noise level. It's there even after the engine has been out this Winter and a lot of parts gone over including a new Waterpump and cam chain. Could be the alternater but thought I should be able to hear it with the cover off.
Also replaced the PCV as I heard they can be quite noisy then they wear. Didn't change a thing. Listening to the PCV from the engine compartment it makes a humming sound but not very loud I think, but still, there's quite a bit of noise back there (engine has quite an aggresive cam).
Would there be different PCVs to try out, and has anyone experienced this before?
Thoughts would be very much appreciated
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