2007 Focus 2.0 Ghia Estate Inaccurate Fuel Readings

[dofez]

Bought the above 3/4 months ago from a franchised dealer. Immediately had a problem whereby the fuel gauge went from having a reasonable amount (displaying 50 miles or so) of fuel to completely empty overnight to the point where the car wouldn't start. Took it back to the dealer who diagnosed a faulty sender unit which they replaced.

Thought nothing more of it until last week when the car wouldn't start. The gauge was reading 67 miles to empty and the warning light wasn't on. Went and got £5 worth of fuel, and as soon as I added it the car started, so it was evidently without fuel again, despite the reading. Additionally, while its obviously not the most economical car fuel wise, it feels like the gauge is moving more quickly than it should. Probably completely irrelevant but its parked on an upward slope if that matters.

Went back to the garage again and their diagnostics are telling them are the readings are accurate, despite the evidence to the contrary. They are now (I think) fobbing me off by telling me they are in conversation with Ford technical seeking advice. I am starting to think they don't want the expense of dealing with a 4 year old car warranty with a defect they have to cover under their guarantee. Might be me being paranoid though!

Can anyone suggest what might be the cause/what action I might take next? Is it worth me taking the car somewhere else to run the diagnostics or could it be something else? Anyone with similar issues make suggestions?

Thanks.

[catch]

Welcome to the forum,

yes you may be being a bit paranoid,they may be seeking feed back from Ford. Whilst I accept you should expect the low petrol warning to be fairly accurate. I've found with mine on the one occasion I let it run that low, when I brimmed the tank it was proved to be under reading actual miles left in the tank.

Do you make a habit of running on what can be termed as an empty tank? Not meaning to come over as being derogatory, I just don't think sucking up the dregs of the fuel tank, is best practice.

Anyway that aside, have you tried running the fuel low again, but parking the car over night facing engine down hill. Then next morning seeing if it starts OK. If it does, don't take the car out, just turn it around with the engine facing up hill. Leave it over night, and see if it will start the following morning. Sometimes it's a process of elimination that is needed to offer clues up to highlight possible cause and effects of a problem.

[dofez]

Thanks - I'll maybe try that. Might have to monitor the consumption manually somehow too to see if petrol is escaping (can't see/smell any leak)

I wouldn't say I usually run it on empty. I wouldn't generally drive more than 5/10 miles after the warning light comes on - and would usually fill before if convenient. Problem here is that last time this happened the dash was showing 67 miles and the warning light hadn't yet come on (not sure when that happens). Then a few days later (we went away from the weekend - might be relevant that it wasn't driven for a few days?) it was apparently completely empty (and wouldn't start) despite still not registering as empty.

I don't think its usual for the fuel readings to be that unreliable (or at least its not on any half decent car I have had in recent years). The fact that Ford are telling me the diagnostics show the readings are accurate is what's confusing me most. I was hoping I might be able to find some sort of known fault on here.

[catch]

The low fuel warning light is supposed to come when there is 50 mile worth of fuel in the tank. And I agree if it has this aid on the car it is not unreasonable to expect it to work.

And as to "maybe" trying that, come on it's hardly like having to rip floor boards up, just parking the motor the opposite way around, now is it.

[dofez]

You haven't seen where I park! Although writing the car off by trying to reverse park might be a viable option if I can't get to the bottom of this :)

Back on the fuel thing. The gauge is currently showing half a tank, pretty much dead on. And the reading is 179 miles until empty.

Does that seem reasonable to anyone with experience of this model?

[kevin lancelott]

Once it hits 50 miles to empty it is surprising how quick it does go.I have the 1.6tdci fiesta and on the rare occasion it got that low the last 50 miles do fly by.You don't want it to get any where near the empty all the time anyway you be getting all the dregs from the bottom of your tank.On another note I had a courtesy car the other week.A new fiesta like mine and I drove from Fleetwood back to North Wales with the petrol light on and that is a 2 hour drive.Thumbs up to the diesel fiesta.