944S2 Noises

[carmunicate]

My S2 has developed a strange vibration, noticable from 2500 rpm when warm, there is a noise similar to a wheel bearing whine, but constant regardless of road speed or engine speed. It is still there when the clutch is engaged/ disengaged so I have disregarded
gearbox. It is noticable when stationary. I have also recently replaced the engine mountings, has anyone any idea where to look ? help, please.

[carmunicate]

Cam chain tensioner checked and seems OK, Belts at the front are a possiblity, but am wondering if the nearside engine mount could be the problem, is there any obvious way of checking this ?