Ringing Sound Under Car – Engine Running

Failed Exhaust Clamp. There are two scenarios that are most likely when you hear ringing under the car when the engine is running:

1. First, your U-Bolt clamp may have rusted and given way, potentially causing an exhaust leak and at the very least, an annoying ringing noise. This is definitely a situation where the clamp’s quality comes into play.

2. The second failure comes from mechanics or DIYers who re-use clamps that have already been in service. When the clamp is properly tightened, the U-Bolt is stretched slightly beyond its original shape. This ensures that it stays tight for the life of the exhaust system. When re-using a clamp that has been previously stretched, the metal weakens significantly and increases the chances of breakage during operation.