I have a 2015 Silverado when i start truck makes a sound like it has an exhaust leak. Took it. In for that was told it had no exhaust leak. Only make sound when i start truck then goes away. Anyone have any idea why this is happening. Truck runs fine just make noise when starting.

Thank you

 

could be a leak that only happens when the pipes are cold then once it warms up the metal expands and seals the leak. with the engine cold i would try to feel around the exhaust to see if i could feel and air being pushed out

 

I took it to an exhaust shop and they couldnt find anything.

 

Is this in the engine area or the pipes?

You might have a broken exhaust bolt or bolts. When the manifold heats up and expands, the leak is closed.

Check your plugs as well and make sure none are loose.