: 91 Brougham 5.0 TBI gas tank pressure

12-14-09, 09:14 PM
When I go to fuel up and take off the gas cap, a lot of air rushes out as though it's pressurized. Should it do that? Should the cap be vented?


12-14-09, 09:41 PM
No, it is a sealed system. In fact, you will fail an emissions test immediately if the cap won't hold pressure. There is likely a warning label telling you that you should open the cap slowly because of the rushing air. Happens on my FI cars, too when the tank is low.

12-15-09, 02:11 PM
Mine also does that.