Whistling Noise from Fuel Fill Area -- Fixed!
 

Vehicle: 2000 base 2.7L

Issue: classic "blowing over a bottle noise" from fuel filler area. No CELs/codes. No issues filling with fuel. No issues starting after fueling. Noise would appear under light engine load. No noise during idle or hard acceleration. Noise was very irritating to passenger seat safety device, which in turn, irritated driver.

Resolution: replaced p/n 996 110 129 06 "Fuel Vapor Regeneration Valve" which is located under the intake manifold, driver's side. It took me around an hour to complete the job (for a skilled DIY or pro technician, about 20 minutes).

It's probably just me, but it seems to me that the engine idles a bit smoother, especially under load, and has just a bit more zip under acceleration. Additionally, the passenger seat safety device is much quieter, at least until around 4000 rpm...

I'm fairly certain the correct term for the passenger seat safety device is the Nagigator :D

I've had this same sound since I've had the car but its never bothered me much. Does it need to be fixed or is it a relatively harmless issue?

almost a $230 part, I would also like to know if this is a relatively harmless issue.

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?

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.

Good info. Thanks.

As to hard to fill, when I bought it was in Los Angles. The first time I tried to fill was outside of town heading to SLC. I could only get $.05 at a time in it and 30 min later the pump timed out like 10 times and I was barely at 1/2 tank. Since getting to SLC it has never done that. It had to be the vapor recovery type nozzle. Only explanation.

Same here. Tried turning the nozzle up side down. Burped gas all over me and the ground. And this is your "Green State" improving the environment. Since then that Gas Station has had several upgrades to the environmentally good vapor recovery nozzles. Now they seem to work O.K. - at last.

It's actually pretty easy to diagnose. All you have to do is pinch off the rubber part of the evap hose right at the throttle body then if the car starts easily there's no Whistling noise and if it is easy to fill the gas tank, then it's probably the EVAP valve.