saulgdman

I have a 2017 RX450h that I've owned for about 6 months now. About 50-70% of the time when filling the tank (at various stations: e.g. Shell, Costco, Citgo) gas will spill out of the fill neck when the pump shuts off (auto shut-off). I do NOT top off my tank - I always let it auto shut off and stop. This causes fuel to leak into the fuel door area and down the side of the vehicle. In total, I'd estimate about 2-6 oz of fuel spills each time. It would appear this is from overfilling. I have not had this problem on previous vehicles (had a 2008 highlander prior to getting the RX). Has anyone else had this happen? I'm concerned it might start causing paint problems.

dibl

That's not good. Google can find many articles like this one: https://clark.com/cars/why-you-shoul...your-gas-tank/

Cocal

I don't think this is a car problem, but a pump problem as the pump is supposed to shut off on back pressure.

Tarkus

I've never experienced this on any car I have ever owned. It is unsafe. Have you consulted your dealer?

Cocal

It's NOT a vehicle problem, It's a PUMP problem

saulgdman

As mentioned, it happens at different stations, different pumps.

john341

Are you opening the fuel fill door and waiting more than 10 minutes, before pumping gas into the car? There, should be warning on the fuel fill door regarding fuel spill.

c3uo

Funny, but I've had the same problem as the OP with my 450h. I'd say 50% of the time it spills over instead of stopping at various stations. I've learned to be very careful to ensure the nozzle is fully inserted deeply in the tank and watch closely.

MKenM

As stated above, the nozzle needs to be firmly seated in the tank. If it is not too much air will escape which in turn will create less back pressure and until a small bit of fuel hits the nozzle to create that extra bit of back pressure that causes your problem.

Cocal

Doesn't matter it's still the pump. How do you think the vehicle is supposed to stop the flow?

raylor4

Mine's just the opposite. The pump shuts off way before it's full. I have to reduce the flow to slow, or just squeeze the handle a little to fill it. I've never had gas overflow when the filler neck is all the way in. I have no advice, other than to check with the dealer. Maybe there's something wrong with that charcoal canister, or the monthly purge that's automatic. People have asked "What's that whirring sound I hear about a half hour after the car's shut off?" Ray A.

saulgdman

Not sure. I know the nozzle is all the way in. I drive over 30K miles a year so this isn't my first rodeo at the gas pump. I've used nozzles with and without the splash shield and I get overflow with both of them. I never had an issue with my highlander, just the RX450h. I think I'll need to check with the dealer.

From what I DO know, the nozzles are designed to sense when the tank is full by sucking air into the venturi tube in the nozzle until the tank is full and then it sucks gas causing the auto shut-off to kick in. The design of the filler neck could, in theory, impact the ability of the auto shut-off to function correctly.

dibl

The evap control canister was probably long ago destroyed by repeated over flows.

Cocal

That's right, the nozzle senses back pressure as air is being displaced by fuel, and when it reaches a certain point it shuts off, many stations raise this point just so that one can pump more gas into the tank and often this point is too high and causes an overflow.

Tarkus

See the last paragraph. There are multiple causes for this to problem to happen. Logic dictates that if the problem occurs at multiple stations it most likely is the vehicle that is at fault.

https://itstillruns.com/function-gas-cap-7314551.html