I have a loud squealing coming from my ca18det, i thought it would be the timing belt being a bit slack so i tightened up the eccentric shaft and applied some silicon spray for good measure but didn't do a thing. still the same noise increasing with revs. the other thing i could think of was that maybe the bearings are gone in on of the accessories.
Should i get some proper belt spray? i can't soap it up cos of the cover, that and it is toothed.

Never heard cog belts do that. I'd be looking at the accesories. Fit a length of heater hose to your ear, and put the other end on the alternator, etc. until you find the noisy part.

You really need to replace the bearings when you replace the belt.
bet one of the bearings that the belt runs on is dry.