Running on empty!

[Scamp's Walker]

Not sure if this is a common problem with e39s but at 50 miles from empty dashboard light comes on, at 31 miles from empty the dashboard warns me I have 31 miles to go then.... the computer has a mind of its own. Arrived home on Sunday with 31 miles to go started car today with 13 miles to go. Is this usual or does it mean something is on the way out? Also, have been told that if the computised readout flatlines (ie shows no miles)more than once in a while you should replace the fuel filter as it will have probably got clogged up by the "bits" from the bottom of the tank! As the computer seems to regularly flatline should I replace it as a precaution? However, if what I have been told is a load of rubbish, how will I know when the filter needs replacing? Thanks

Edited by Scamp's Walker on Wednesday 6th June 22:13

[M5Dave]

The computer on mine does the same, after the 31 miles warning it goes down very quickly. I don't think it's a fault, I think it's just to prompt you to fill up sooner rather than later.

I've never heard the thing about the fuel filter. If the car's running ok then I wouldn't be replacing it, I think it should be replaced regardless at every inspection 2.

[dcb]

Scamp's Walker said:

Not sure if this is a common problem with e39s but at 50 mile sfrom empty dashboard loght comes on, st 31 miles from empty the dashboard warns me I have 31 miles to go then.... the computer has a mind of its own. Arrived home on Sunday with 31 miles to go started car today with 13 miles to go. Is this usual or does it mean something is on the way out?

Nothing wrong, AFAIK. It's just the computer guessing
at the current state of play.

I can confirm that once the yellow light has been on
for about fifty miles the fuel computer will then
go to zero and there is *at least* thirty miles of petrol
left in it at 80 ish mph.

Mind you, on reaching the Belgian petrol station,
I did manage to put 72.5 liters into a 70 liter tank !

Scamp's Walker said:

Also, have been told that if the computer flat lines (ie shows no miles)more than once in a while you should replace the fuel filter as it will have probably got clogged up by the "bits" from the bottom of the tank!

"Paying more taxes helps change the weather" kind of story.

[Scamp's Walker]

Thanks for the responses, thought it was just mine that was doing it! Also, pleased that the "flatlining" gives me some leeway in an emergency when local petrol stations are closed and a jaunt to the supermarket always seems like the only option. Am guessing that it would be obvious, even to the novice, if the fuel filter was blocked....VERY poor economy and impaired performance at least I would suspect!

[rassi]

The discrepancy between the initial range, and the range when you started it up is simply down to the fact that the OBC calculates range based on current values. So when you start the car cold, the MPG will of course be far off what a fully warm engine does, hence the much lower range.

[jj.]

dcb said:

Mind you, on reaching the Belgian petrol station,
I did manage to put 72.5 liters into a 70 liter tank !

That's impressive, I thought I was doing well to get 68.7 litres into my E39.
jj