Report: Buzzing Noise from Exhaust at Different Engine Speeds
Ford E-150 Problem
Average Mileage: 79,000 mi (62,000 mi - 96,000 mi)
If a buzzing noise is coming from the exhaust at different engine speeds and conditions, this is commonly caused by the heat shields on catalytic converters coming loose at points. The buzzing is the metal on metal contact. Installing a large worm clamp around the catalytic converter and heat shield assembly will prevent the noise and secure the shields.