Why does my gas cap keep loosening on my '02 Passat?
My gas cap keeps coming loose even though I make sure to turn it good and tight, click, click, click. I can tell immediately when it starts to loosen, the car starts to run really rough and on a hill there will be no oomph (feels like we're not going to make it). Stop the car, turn it off, take off the gas cap, put it back on, and then we are good to go again, but for increasingly shorter distances. I bought a new gas cap. Very same thing happens.