Hello, new to this forum. On my '03 f-20 crew cab with 7.3l diesel, when the fuel tank is below 1/4 and the overhead console is showing approximately 65 miles to empty, the engines rattles real bad like it's sucking air. Local dealer replaced the fill tube and bell shaped strainer below the fuel pump in the tank; didn't help. Anyone got any answers?

who6386 said:

Hello, new to this forum. On my '03 f-20 crew cab with 7.3l diesel, when the fuel tank is below 1/4 and the overhead console is showing approximately 65 miles to empty, the engines rattles real bad like it's sucking air. Local dealer replaced the fill tube and bell shaped strainer below the fuel pump in the tank; didn't help. Anyone got any answers?

Click to expand...

Any shortage of fuel in a diesel will start your "rattle" noise. Newer diesels have a strategy to shut off injectors as a "fail safe" to prevent damage. And remember, any trash will more likely show when the fuel level is at its lowest. Without running fuel pressure tests and other diagnostics, I can only guess at the cause. Because it only shows at low fuel levels, I'd say its getting air in the system.

Hey thanks for the info. Me and the dealer kinda thought that might be the problem. Only problem is, finding out where the air is coming from. 'spose to take it back to the dealer tomorrow, who really doesn't have a clue as to what to do.

very interesting indeed. A new pickup tube didnt help?
What did the inside of the tank look like?

Thanks for your info. The mechanic said that the inside of the fuel tank looked reasonably clean for 242k miles.

More in depth diagnostics need to be performed. Checking integrity of fuel lines from the in tank module to the frame. Then from the frame to the secondary fuel filter. This will show if you're sucking air from anything after the tank.

who6386 said:

Hello, new to this forum. On my '03 f-20 crew cab with 7.3l diesel, when the fuel tank is below 1/4 and the overhead console is showing approximately 65 miles to empty, the engines rattles real bad like it's sucking air. Local dealer replaced the fill tube and bell shaped strainer below the fuel pump in the tank; didn't help. Anyone got any answers?

Click to expand...

blacksnapon said:

More in depth diagnostics need to be performed. Checking integrity of fuel lines from the in tank module to the frame. Then from the frame to the secondary fuel filter. This will show if you're sucking air from anything after the tank.

Click to expand...

Perform the tests that Vince mentioned, but since it only does it with low fuel level, I suspect the fuel level is lower than the gauge or overhead console are displaying. I have never trusted fuel gauges (to may years with off highway vehicles that have piss poor fuel gauges) and always go by actual miles driven to hand calculate gallons used. You may very well have a fuel gauge or sender issue and are running the tank dry causing the fuel pickup to become exposed & suck air. You definitly want to find the cause and remedy the situation as low fuel supply is hard on injectors.

Thanks, guys. I'll pass this info on to the Ford mechanic.