What causes a gas smell in a Chevrolet Corvette C6?

The most common cause of a strong raw gas smell in a C6 Corvette is a cracked plastic elbow fitting on top of the driver's side fuel pump module ¹⁰. This crack allows fuel vapors and liquid gas to escape, which is why the smell is usually strongest inside the cabin or your garage right after filling the tank past the halfway mark ¹¹.

To diagnose it, inspect the driver's side fuel tank behind the rear wheel. If that upper fitting is cracked, you will often see gas stains, sticky residue, or wet fuel running down the side or back of the tank ².

Other potential causes to check before you commit to dropping the fuel tank:

• Fuel Crossover Tube: The tube connecting the left and right tanks can leak at the fittings ¹.
• EVAP System: A worn-out EVAP canister can release vapors while driving, or cause the fuel pump nozzle to shut off repeatedly while you are trying to fill up ¹⁰.
• Gas Cap: A faulty gas cap that no longer clicks when tightened can allow fumes to escape overnight ².

Repair Overview & Difficulty

Difficulty: Hard to Expert

Replacing the fuel pump module is labor-intensive because it requires dropping the driver's side fuel tank.

• Manual Transmissions (M6): This is the easier configuration, though still a heavy job. The hardest part of reassembly is compressing the crossover pipe perfectly straight so you don't damage the internal O-rings ⁴. Use plenty of grease or lube on the O-rings going back together.
• Automatic Transmissions (A6): This is notoriously difficult due to packaging. Standard procedure often involves dropping or lowering the driveline and transmission to get clearance. Some experienced DIYers manage the job on jack stands without dropping the transmission by fabricating custom tools to compress the crossover pipe, but space is extremely tight ⁶.

Note on GM Coverage: GM originally issued a special coverage program (TSB 15682) that covered this exact fuel pump repair for 10 years or 120,000 miles from the original in-service date ¹². Because the newest C6 is a 2013, all of these cars have aged out of that coverage window, meaning this is now strictly an out-of-pocket or DIY repair ⁴.

Safety & Workaround

Gas fumes accumulating in an enclosed garage present a serious fire hazard ¹². Until you have the time or budget to replace the pump, a proven workaround is to simply keep the fuel level below half a tank. This keeps liquid fuel away from the cracked upper fitting and will significantly reduce or completely stop the smell ³.