What to Do If the Fuel Tank Cap Won't Open?
2 Answers
Solutions for a fuel tank cap that won't open: 1. Check if the cap is stuck or the hinge is rusted. You can insert a small wooden piece into the gap of the fuel tank cap to pry it open while simultaneously pulling the fuel tank cap release switch. 2. If the fuel tank cap spring has lost its elasticity, you can add a small spring to the rubber pad on the fuel tank's protrusion to increase the elasticity between the cap and the locking mechanism. 3. Some vehicles have thinner sheet metal, which may cause the fuel tank cap to be misaligned. Visit a repair shop to have it realigned and reinstalled. 4. If the fuel tank cap hinge or latch is aging, apply lubricant to these areas. If the fuel tank cap is frozen due to cold weather or too dirty to open, address the issue first without forcing it open to avoid secondary damage.
If you encounter a fuel tank cap that won't open, it's mostly due to a stuck cable or a rusted lock cylinder. I've noticed many vehicles are prone to this issue during cold and humid seasons, likely caused by aging sealing rubber or imbalanced air pressure inside and outside the tank. Don't yank it forcefully in such cases. First, use a heat gun to blow warm air around the fuel cap for a few minutes to soften the rubber seal, while having someone continuously press the car door unlock button to repeatedly lock and unlock it. Some car models have an emergency pull ring inside the trunk—check near the rear of the vehicle. If it still won't open, spray some WD-40 lubricant into the lock cylinder, let it sit for half an hour to penetrate, then try again. If all else fails, you'll have to visit a repair shop to remove the interior trim and fix the cable. Never use a screwdriver to pry it open forcefully—if the fuel cap gets deformed, you'll end up spending a lot more to replace it.
