Alfa romeo 147 hard gear strange engine noise

Question

I have an alfa romeo 147 2007, lately the gear got so hard,and i also noticed some oil on the ground where i park the car, and today i noticed when i accelerate the engine is making a strange noise like its pulling air into the engine, a very strange noise. I checked the engine oil and the water all good. What could be the issue? The gear oil? Could it cause such a noise in the engine? Thank you