Has anyone experienced a loud pop in the engine compartment when first stating their engine when it is cold? This seems to be worse if the gas tank has recently been filled. Can sometimes be subdued pop but can also be a very loud bang. Been to dealer twice with no results. If a trouble code is not displayed they are clueless.

 

What model year vehicle do you have? I would like to see if I can assist you. Thank you.

Jeff Morris, Chevrolet Customer Service

 

This is a 2006 trailblazer LT 4fd with the 4.2 liter L-6 engine.