All of it. The 10 percent figure you occasionally see is nonsense that a lot of people believe just because they've seen it so much.
Quick Answer. Some things that cause a vehicle's front end to make a clunking noise are worn ball joints, a damaged tie rod, broken or loose sway-bar links, hard or damaged shocks, and faulty shock mounts. An automotive professional can inspect the vehicle's front end to locate the source of the clunk. Continue Reading.
Stray sounds are highly unlikely to involve the engine, unless they are related to engine movement under acceleration. Try sitting in the car with the engine off and having somebody push down on the bumper or the trunk a few times, and see if that causes the noise to occur. Return to Diagnostic Chart.