Evap purge valve opening up.Good afternoon, Forum
I recently purchased a 2016 Colorado Z71 and noticed a noise while idling that I am hoping you can help clarify.
I heard the noise one day while sitting in the garage with my wife before leaving our house. After sitting there for a while, I noticed that the truck started to sputter, or bog down, for a few seconds, then it went back to idling normally.
This alarmed me, so I attempted to replicate the problem. What I found, after several mornings of recording the truck idling, is that the noise occurs approximately 3:45 after starting the truck. It's like clockwork. It lasts for about 5-10 seconds and then returns to idling normally. I've only noticed the "sputtering" after the truck has sat in my garage overnight. As I left my house this morning, it started to sputter and sounded like it was going to stall, but the RPMs weren't dipping at all.
Does anyone know what may be causing this? Given the consistency in the time of the occurrence, it almost seems to be by design. Is there a secondary process that is taking place that would cause the engine to bog down momentarily?
I apologize for the long message. Just wanted to be a thorough as possible.
Any help would be greatly appreciated!
Once the engine has hit a specified warm up temp, to burn off gas fumes from the fuel tank. The opening causes a momentary lean condition, until the computer compensates, so the engine kinda hiccups during it.
And Welcome aboard.