How reliable is the Ford Ecoboost engine?

[mizterwizard]

The EPA does not want you to top off because any spillage is a fuel emission. Whether the first shutoff is good enough or not is largely a function of the tank venting system.

When you put fuel in the tank, the air inside has to go somewhere. Some tanks vent well and top right up. Other tanks don't vent well so the air and fumes have to come back up the filler neck. When that happens it can cause fuel to come out with the air.

The way the shutoff works is there is a small tube that extends down the nozzle. When fuel flows past the end of the tube it creates a slight vacuum in the tube. When the fuel meets resistance in the filler neck because there is liquid at the end of the nozzle or some obstruction, the vacuum decreases. The valve in the nozzle, that is under the big bolt between the handle and the nozzle, gets pressure instead of vacuum it trips and shuts off the fuel flow.

Fuel that burps back up the filler neck can trip the valve in the nozzle and it will shut off. This is a good thing for several reasons, not the least of which is that it protects your shoes from getting stinky.

Every OEM fuel tank is built with the filler neck entering the tank below the top. There is always a bulge in the top of the tank to allow for expansion. The carbon canister takes fumes from that bulge to reduce emissions. It does this both while driving and while refueling.

I haven't seen a vapor recovery hose on a filler hose in a long time. The carbon canister technology on the car is supposed to make that unnecessary. I guess some jurisdictions still want to play it safe with a belt and suspenders solution.

It is possible, on some vehicles, to fill the bulge on top of the tank by filling the filler neck and letting the pressure push fumes out of the bulge and into the carbon canister. This is not a common problem though.

In order to minimize the size of the carbon canister there is nearly always a pressure relief valve in the vent system. With the gas cap on, the system will build a bit of pressure which means that the vapors are not entering the canister yet. By holding a little pressure in the tank the fuel will evaporate slower which will reduce the load on the carbon canister. Only when the pressure becomes high enough will it actually vent. The pressure it takes to open the relief valve is more than can be built in the filler neck so there is little chance of fueling directly into the canister.

If the vent pressure relief valve leaks the computer will detect it and set a code. If you don't have a CEL then your valve is working okay.

The amount of pressure the fuel can make is regulated by the EPA. It's called Reid vapor pressure. The higher the temperature the higher the pressure. If the fuel tank pressure sensor does not indicate the expected pressure relative to the temperature then the computer suspects either a leak or wrong fuel. The whole system is called EVAP and diagnosing an EVAP code can be pretty tough.

[mizterwizard]

Overfueling into the carbon canister will render it useless until it dries out. Then it will return to normal. It will not be ruined, typically. The engine draws fresh air through the carbon canister and into the intake. This removes the gasoline from the carbon, whether it is vapors or liquid.

There is a lot of variability in the quality of mechanics. Some will diagnose the problem and fix it right but others will just replace the parts they know will make the problem go away without really finding out what is wrong.

Since EVAP problems are tough to diagnose, a lot of lesser mechanics will just replace hoses, valves and the carbon canister as a set. That will fix many problems but it isn't the best solution.

Such mechanics will blame the problem on mis-fueling and ruined parts when in reality it may have been a leaky gas cap.

Now if you have to pass a smog test today to be able to leave on your trip tomorrow then maybe just throwing a new carbon canister and set of hoses on the vehicle, clearing the code and driving it until the monitors clear is a good idea.

[Brian B-P]

Originally Posted by mizterwizard

I haven't seen a vapor recovery hose on a filler hose in a long time. The carbon canister technology on the car is supposed to make that unnecessary. I guess some jurisdictions still want to play it safe with a belt and suspenders solution.

We never had them here. In the U.S., they were apparently phased out starting in 2012, but some places (such as Rhode Island) took a long time.

[mizterwizard]

Originally Posted by Brian B-P

We never had them here. In the U.S., they were apparently phased out starting in 2012, but some places (such as Rhode Island) took a long time.

Not being a national traveler, I wasn't sure if there weren't some places that still had them. I was a GM mechanic at the time they came and went. I asked one of my instructors at school about it and he said that the vapor hose technology had been leapfrogged by the EVAP technology. You just never know what some state or other is going to do though.

[gbaglo]

Chrysler Neon company car ( new in 2,000 ) would shut down the pump when the tank was only 2/3 full. Charged on the company card, I always pulled into the full service lane, even if it cost more, so it wasn't my fault. But, it was annoying.

I think the three photogs still working at the Sun are still driving those cars.

[TNOutback]

Originally Posted by Hilola

I was talking to my step-son (who is a bit of a backyard mechanic) and was advised to steer clear of the ecoboost engines as they have issues with carbon building up in them, or something to that effect. I don't have any detail beyond that but he was told this by a friend who is a Ford master mechanic. His friend said it's an issue which Ford has been keeping under wraps.

Would like to here from actual owners about your personal experiences and your mileage.

Don't shoot me, I'm only telling you what I was told.

2016 F-150 4x4 Crew with EB. Absolutely love this truck. Power is awesome, smooth, quiet, comfortable truck. Never any problems. I get 22 -22.5 MPG highway IF I drive the speed limit.