5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
hi to all,
does anyone know why my fuel consumption gauge, the half moon shaped one under tacho, all of a sudden has gone crazy???
when car is off, its at 0
when driving it moves around, but doesnt really look like its stable.
when im idling, its at maximum fuel consumption, actually so high, i cant see the needle..and have noticed on obc, that my consumption levels have risen from 11.5-12.6 average, to 15 and climbing still...(thats lt/100km).
1. When it's off, you're using no fuel ...
2. It's by no means accurate; it's pretty much dependent on throttle inputs to get it's estimation.
3. Think about it. You're idling, therefore fuel is being used, yet you're getting no movement. You could use up a 1000 liters and not move at all, so yes, the consumption average will climb on the OBC, just like it does mathematically if you were to calculate it yourself.
4. You're being paranoid.
If it does not look stable,it should sweep back and forth slowly on gentle throttle and nip back sharpish to near zero when cars given some,then check under the drivers dash knee high panel,on my 94 tds the sensor that works it lives there,mine has a vacuum connection to it (diesel turbo) plus the multiplug,yours may have a vacuum connection and maybe dodgy engine vacuum or leaking pipe is confusing it.As for tickover it goes off and no throttle at speed in my autobox equipped car it will show about 20mpg at 80mph simply because the box is in 5th gear lock up mode,other gears coasting the engine drops to tickover and it goes off with needle dropping back past zero to its home position.Driving at constant speed the needle should stay still,slight on or off throttle will get it to move either way,and a boot full gets it to move quickly to 15/20mpg,yours may well move quicker as yours is not capable of near 50mpg.
problem still not resolved...
i will look under dash and let you know what i find.
but idling, i notice on obc that consumption reaches and passes 40lt/100km, and gauge is higher than maximum, it used to sit on 0 when idling, then i must of touched something under dash, when i tried to get to brake light switch, since then its gone crazy..
so you say under dash, can you describe exactly what im looking for, cause i think that could be the problem.
When you take the panel out that fits in front of your knees,the padded one,on the back should be a small box about half the size of a cigarette packet,this has a multi plug that has around about 7/8 thin wires going in it,and the vacuum pipe goes into one side of it.When I first see this on my car I thought it was the buzzer or gong for the 'lights on alarm' and then I clocked the vacuum pipe and the multiplug,the multi plug wiring is traceable back to the throttle pedal potentiometer so if yours is not on the back of the panel then follow the wiring from the throttle pedal to find it.
If your ECO gauge is not 'working right', I would suspect that the gauge is correct and there is a problem elsewhere on the car. It's true that these cars figure MPG as an average....so when you are idling, you SHOULD register a 0 MPG....because you are using fuel but not accumulating milage. This is why the OBC MPG and consumption figures are incorrect.
If anything, I would say that the ECO gauge was incorrect for the first month, and is now correct and functioning properly.
I have a quick suggestion. Fill up your tank with gas. Reset your trip odometer. Drive until you have used 3/4 of a tank of gas. Fill it up. See how many miles you drove via your trip odometer. Divide the miles by the gallons used and that is your gas mileage. This is how we did it before we had fancy computers. These cars get horrible gas mileage, I don't care what year or model it is. That floating mpg indicator is so inaccurate. They just put it there so it looks cool. But, guess what? You don't by a bmw because you care about gas mileage. Drive it and enjoy. If you want 30mpg, buy a japanese econobox. That is what I drive when gas costs $4.55 per gallon. My Bmw sits in the garage.
well looked where you told me to look, MADDOUG, all i have after i remove the panel is the gong, with 2 sets of wires coming out of it, and the a/c tube that goes to feet...
im talking about drivers side, right hand drive bmw...nothing else behind panel thats knee height.
will look on throttle pedal next, to see if i can locate any wires...will let you know..
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