Whistling Noise from Fuel Fill Area -- Fixed!

[Timco]

Originally Posted by Need_for_speed

My understanding is that this issue begins as a harmless problem that gradually progresses to something you'll be forced to address. Apparently, trace amounts of fuel contaminants will start to build up in the valve and hose and start to cause the whistling noise. Eventually, the buildup will become so adverse as to cause difficulty fueling, hard starting after refueling, as well as triggering various fuel evap system codes. This problem is a bit tricky to diagnose, as there are several components in the fuel evap system that can cause this issue.

How does this issue affect starting? Fellow member has the won't start after fill up issue but not the noise. How do you test this part / diagnose?

[Need_for_speed]

Originally Posted by Timco

How does this issue affect starting? Fellow member has the won't start after fill up issue but not the noise. How do you test this part / diagnose?

From the research I've done on this and other forums, my understanding is that this component can cause the hard to start after fuel fill issue, or it can cause the noise, or it can make it difficult to fill the tank, or it can cause all of the above or some combination thereof. To make things even more complicated, this component can fail along with one of the other multiple purge valves in the evap system and make things really exciting. I've also read of instances of cracked charcoal canisters and clogged evap lines. I believe you can test the valves via Durametric or PIWIS, or you can use a 12 volt battery. There are two valves in the right front fender behind the headlight assembly. I tested both at the outset: one tested good, the other inconclusive, so I just replaced them both. Unfortunately, that did not solve the problem. Replacing the regen valve was my next best guess, and turned out to be the cure.