It could just be (if the reel is pretty new) that it's time to oil the bearings - easy enough to do with the oil of your choice. If you're in any doubt, the man to see would be Ronnie at I D Fishing in Byker.
Also bear in mind that the Penns are fairly noisy reels anyway - I've got a couple of 525's and they're way noisier than any of my Daiwas & Abus. I've fished with some lads whose 525s
really scream; just the nature of the beast I reckon.
Cheers, Gary