Hello all,

I accidently overfilled my car the other day while trying to squeeze in little more gas after the first click. I immediately noticed it was spilling and removed the nozzle. This is my first time ever overfilling and I know it is always advised not to overfill. Is there anyway to know if I caused any damage to the car including the EVAP system?

 

Um….no damage except to your wallet. Excess gas goes straight to the ground via the overflow drain hole just under the hole where gas goes in.

 

The potential is a bit worse than just a dime of gas on the ground (and it's doubtful you spilled more than that because a little goes a long way).

As you presumed, the biggest risk is getting liquid gas (vs fumes) into the EVAP system. That can clog up the system and cause the car to run rough. The system also requires some space for heat/expansion, so that the fuel doesn't spill out and create a fire hazard. Overfilling one or twice is probably not going to cause a big problem. If the car starts to run rough, that's a sign you buggered the charcoal filter. I haven't specifically priced one for the F-Type, but they can run up to (and over) $1,000 on some cars, installed.

 

Thanks. Is there a way to check if the liquid got into the EVAP and ended up clogging it, even if slightly? Would the damage be limited to just the evap system or could there be other ramifications throughout the engine?

 

The filler is designed to allow for an overfill. It just sends the extra gas to the ground via a tube.

 

Interesting, does that mean overfill would go through the tube before it can leak into the EVAP? It makes sense, if this is the case, it is just hard to understand the caution messages in the manual and other places regarding an overfill damage.

 

The tube connects directly to a nipple on the underside of the overflow hole so unless that tube is blocked there is no way the excess fuel is getting into the EVAP.
Or you can do what I (accidentally) did - remove the tube altogether so there is nothing other than the hole to get blocked.

 

Is it overfill hole the one circled in red?

 

Yep that's it.

 

I'm not sure how much that hole is helping to be honest. It looks like the tank needs to first overfill before that hole can let go off the excess gas or maybe I'm missing something. I feel that hole is helpful for avoiding excess gas spill on the paint but not sure it helps with avoiding excess gas potentially getting into EVAP.

 

The hole is there to drain fuel which splashes into that area from around the fuel filler hole, which can get there in a few ways:
- overfilling the fuel tank (rare but possible)
- clumsy operation / poor aim by whoever is holding the pump nozzle
- dodgy/poor/splashy pump/nozzle
- trapped air gurgling/burping out and splashing fuel
I don't know for sure but I guess it's also there to drain any water that might get in that area.
And I agree, I struggle to see how fuel can get into the EVAP system hole or no hole.

 

agreed , no way that over filling will ever cause any damage to EVAP. You only need to look at a cross section of the fuel system to see it is impossible . The only way overfilling could cause a issue is if it was like a jet fuel connection being completely sealed with no overflow or escape and pumped in under ridiculously under high pressure (ie: will never happen except maybe on mythbusters)

 

I did that one time trying to get as much gas in the tank as I could prior to a long trip. I think the only damage done was to probably remove the wax from the paint where a few ounces of gas spilled. I used the water hose at the gas station to rinse off the area and then applied some more wax to that area when I got home just to be safe.

 

Just run it. Assessing the failure modes at this point won't do you any good unless you plan to dismantle parts for visual inspection.