I'm not a mechanic, but according to online sources it sends fuel vapors back into the engine to burn. You will need to talk with an actual mechanic or pick pickup a Haynes manual to get a better explanation.
Thanks man my buick had the same problem and one day it just didnt turn on any more A local shop said its the timing chain but i think its that purg valve yu mentioned I think that they just want to rip me off because just to drop the engine and look at it is gunna be 2600 😰
@@hbg7078 I replaced it. Sometimes it can be impacted by other problems so it may not be a bad idea to have a mechanic check it. Due to the age and mileage I have on mines other parts are starting to wear down. I like the Enclave but it maybe time to trade her in.
It does exactly what @Peter Dixon says it does. A Purge Valve is part of the engines environmental controls. It gathers fuel vapors and re-condenses them back into the Engine to be burned off while the vehicle is running. This is also why it is advisable not to over fill your Fuel Tank as it will flood out the Charcoal Vapor Canister and prevent it from working properly and possibly destroy it...an expensive repair!