I have a 1998 Stingray with a Mercruiser 3.0 alpha one engine. Since I got the boat back there is a creaking/squeaking noise when you engage the engine. As you accelerate the pitch of the noise goes higher and then stops once you're over about 5 mph. What could I check? I want to ensure that all the fluids are fine and the dealer didn't screw anything up after bringing it out of winterization.