Coke Bottle Noise / Fuel Filler Howling Noise

[spinjockey]

Originally Posted by Rob175

Last fall, when I stored my 98' Boxster for the winter, I topped off the fuel tank as I always have done in the past along with a can of SeaFoam. But this time I really topped it off.

As I drove the 15 miles to it's storage location all was good until the last 2 miles when the CEL came on. I used my scanner and determined the code was for the evaporative system. I cleared the code and continued to drive another 25 miles or so, with no CEL lit and assumed I screwed the system up by overfilling and would deal with it in the Spring.

Now, the car is out of storage and I've driven the car another 1,200 miles, still no CEL and the car runs perfectly. Did I dodge a bullet? Did whatever fuel might have flowed into the canister evaporate? Was it just a CEL fault that was triggered?

IF the car runs great, and no CEL light I'm of the mind to just drive and enjoy the car and not worry about it .....am I doing something wrong?

You probably dodged a bullet but have to watch it. The carbon canister gets plugged with repeated overfilling and contamination with age. This makes the carbon more like clay which effects the vacuum in the evap system triggering a CEL in some extreme cases and a howl in others.

[boreo]

Originally Posted by spinjockey

You probably dodged a bullet but have to watch it. The carbon canister gets plugged with repeated overfilling and contamination with age. This makes the carbon more like clay which effects the vacuum in the evap system triggering a CEL in some extreme cases and a howl in others.

I'm wondering if this thread is similar to my issue. Car starts, idles, and drives with no issues. At speeds above 50mph, I get a loud howling noise from the fuel filler area. I replaced the gas cap and no difference. I am repeatedly getting the P0445 (large evap leak) code whenever I give above ~50% throttle when the fuel tank drops below 3/4 of a tank.

Not sure if the plan of attack here should be replacing the purge control valve and charcoal canister at the same time. Or do the charcoal canister first.