Full tank but fuel gauge reading only 3/4. Resetting? - The Unofficial BMW M5 Messageboard (m5board.com)

IvanDias · 3rd August 2006, 19:32

Hi,

After a few months, ok, a year or more, of driving about adding £10/£20/£30 of fuel at a time, I have noticed both times I have recently filled it right up, that the fuel gauge only snaps up to 3/4, not to full.

It certainly did it before.

Does anyone know a way of recalibrating it?

I considered running it completely out and then filling from a can, then tanking up from a petrol station, but a recent post warning that the fuel pump is fuel cooled has put me off. That bit of info certainly seemed logical given that my tank reads empty yet only takes 65 or so litres to fill.

While I'm here, I'd like to point out that the yellow low fuel light has never illuminated on my car, no matter how low the fuel, even after I kicked the engine with under a litre in the tank ages ago.

Regards

Ivan

illjah · 3rd August 2006, 19:42

I found my fuel guage to slowly get more accurate if i filled up every time rather than £10/£20 at a time - as you say be carefull of running too low, as i used to run it really low every time before refil, and we'll i had a fuel pump failure (still worked but undersupplying pressure, but to inspect it looked like it was working) and that caused me all sorts of problems when it ran lean, blew MAF etc etc.

But there might be a more technical way of getting it to read correctly. Have you checked that the needle isn't loose in the display or something silly like that!!

GoneAgain · 3rd August 2006, 19:51

I find that mine sometimes sticks the other way. It will read 40litres in the tank when it's definitely running lower, but only occasionally, but the warning light will still come on at 20 litres.
I tend to use he OBC reading for fuel in the tank ,test 06 or 07 - I find it very accurate.

I think you can set the warning light threshold through the OBC, but not certain & certainly don't know how to do it.

Can't help with your specific problem though!

T