My car has very loud motorboat noise when cranked. It has been maintained well with regular oil changes. I saw a spring-like coil on the ground under the engine, but I'm not sure it came from my car.
On many vehicles, the exhaust joints are held together with bolts that have a spring coil on them and allow for a little movement as the engine twists under load. There is a possibility this coil fell as the result of a broken bolt and the motor boat noise can be a large exhaust leak. I would recommend having an experienced technician look over the exhaust system to detect the cause of the noise.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing