Trip computer and ave consumption accuracy

[frikkieh]

Bmw recommends not driving below 50km on the trip advisor

My new rules are not to go beyond 100km (just before the fuel light comes on).
If I think that I won't make it, I would rather fill it.
The pre-facelift does not have a gong telling you that you are running out after the light came on, but this is just another annoyance to make you put in fuel.
I filled up today, and there is definitely something wrong with the fuel level indicator. The gauge indicates a 3/4 tank and not full.
I don't like to fiddle on fuel systems (boom ! :uhoh: ) so I will have it checked out when the car is almost empty again.

How is a software reset done on the car?

 

[Sankekur]

You can reset most of the stuff by just disconnecting the battery for a couple of minutes.

 

[frikkieh]

Called the stealers 2day. Fuel tank level sensor – 16116766940 – R6 912. :dropjaw:
I think I will spend R200 bucks on a Jerry can

 

[Kyle Xavair Moodley]

ok guys i have a 325i e 46 and that trip comp is stuck on 33.3l/100km:thinking:
:thinking:, my range is accurate but my trip computer never gives me an accurate reading

 

[netercol]

Called the stealers 2day. Fuel tank level sensor – 16116766940 – R6 912

abso-fcuking-lutely mother-f***ing freaking crazy.. is bmw actively trying to drive away their customer base????? :dropjaw:

 

[frikkieh]

Called the stealers 2day. Fuel tank level sensor – 16116766940 – R6 912

abso-fcuking-lutely mother-f***ing freaking crazy.. is bmw actively trying to drive away their customer base????? :dropjaw:

Freak of the week, I'm telling you. We don't call them stealers for nothing. I will try scrapyards. Our supplier in the Moot does not have. Perhaps borrow one from the neighbors car??? :hammerhead:
It's propably a sealed unit with some electronics inside, slimming chances of fixing it on component level. I will call a couple of yards tomorrow and for sure be able to report a better price...but will the secondhand part work? Ten to one, then pray it does not pack up too, then I will have to get used to the jerry can idea. The stealers want to sell me a new car, therefore the extraordinary prices for parts.

 

[Jacques Motorem]

Perhaps the price includes the actual fuel pump itself which is incoporated with the level sensor on the drivers side. (Passenger side has the float level sensor only). Check with scrap yards for a bare level sensor - quite easy to remove if you pour hot water on the internal connecting pipes to get them soft. You should get a used float level for around R350.00.

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the part number above is described as "Plastic fuel tank with left sensor". So you must buy the fuel tank as well?:dropjaw:

 

[frikkieh]

Perhaps the price includes the actual fuel pump itself which is incoporated with the level sensor on the drivers side. (Passenger side has the float level sensor only). Check with scrap yards for a bare level sensor - quite easy to remove if you pour hot water on the internal connecting pipes to get them soft. You should get a used float level for around R350.00.

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the part number above is described as "Plastic fuel tank with left sensor". So you must buy the fuel tank as well?:dropjaw:

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Correct - I called again and found that it is infact the entire assembly - thanks for correcting me. The left sensor is R1378, the right sensor and pump is R4773 and the complete assembly with the fuel tank then is the mentioned R6912. OEM does not list the individual parts - hence the confusion. How do I know for sure that only the left sensor needs attention. Adding L & R parts, I still rock up @ +/- 6k. How good is a used sensor?

 

[Jacques Motorem]

Perhaps the price includes the actual fuel pump itself which is incoporated with the level sensor on the drivers side. (Passenger side has the float level sensor only). Check with scrap yards for a bare level sensor - quite easy to remove if you pour hot water on the internal connecting pipes to get them soft. You should get a used float level for around R350.00.

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the part number above is described as "Plastic fuel tank with left sensor". So you must buy the fuel tank as well?:dropjaw:

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OK so thats the part number for the tank which comes fitted with a new float. Float alone is priced at R1200.00. Not all the part salesmen are clued up it seems.:dunno:

 

[netercol]

lol, that sounds better

 

[Jacques Motorem]

Perhaps the price includes the actual fuel pump itself which is incoporated with the level sensor on the drivers side. (Passenger side has the float level sensor only). Check with scrap yards for a bare level sensor - quite easy to remove if you pour hot water on the internal connecting pipes to get them soft. You should get a used float level for around R350.00.

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the part number above is described as "Plastic fuel tank with left sensor". So you must buy the fuel tank as well?:dropjaw:

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Correct - I called again and found that it is infact the entire assembly - thanks for correcting me. The left sensor is R1378, the right sensor and pump is R4773 and the complete assembly with the fuel tank then is the mentioned R6912. OEM does not list the individual parts - hence the confusion. How do I know for sure that only the left sensor needs attention. Adding L & R parts, I still rock up @ +/- 6k. How good is a used sensor?

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I have had problems with both sides in the past. Faulty passenger side caused gauge to under-read. Faulty drivers side actauly left my wife stranded with empty tank while gauge showed qtr tank. I would remove the passenger one and inspect for any damage or excessive wear on the little "contact electrodes" - it may also just be stuck. We sell used float sensors from time to time and don't recall comebacks.

 

[frikkieh]

So I had both sensors replaced, together with the fuel pump, and after several times of refueling, I can report the following: the trip computer is deadly accurate :thumbsup:
The fuel pump can cause the car to run empty even if there is fuel left in the tank, because of the shape of the tank - which I found true the hard way in Potch one night.

 

[Philip Foglar]

Well for now we are filling the E46 up as soon as it shows the reserve light and/or a remaining range of 100km - the other day we came back from a bit of an outing and the reserve light comes on with the range to empty showing a 100km. We got home with the range to empty showing 50km exactly and after dropping me off, told my Wife to go straight to the petrol station and fill up. Barely made it to the petrol station a few kms away, engine stuttering (just the worst thing to have happen) and from her calculation there must have been 300ml of petrol left in the tank while the range to empty was showing 45km!!! :shocked:

 

[andrewbuch]

Well for now we are filling the E46 up as soon as it shows the reserve light and/or a remaining range of 100km - the other day we came back from a bit of an outing and the reserve light comes on with the range to empty showing a 100km. We got home with the range to empty showing 50km exactly and after dropping me off, told my Wife to go straight to the petrol station and fill up. Barely made it to the petrol station a few kms away, engine stuttering (just the worst thing to have happen) and from her calculation there must have been 300ml of petrol left in the tank while the range to empty was showing 45km!!! :shocked:

My light also comes on at 100km left to empty on the dash..

Filled up the other day put in 62 litres for a 65 litre tank.. and the range showed 105km to empty :dropjaw:

I remember freerider ran out of petrol with his car showing like 70Km to empty..

i wouldnt chance it.. rather fill when the light comes on..

my dad once ran the jeep.. showed him 10KM to empty.. pulled inti the petrol station when it showed 0Km to empty :dropjaw: filled 78 litres into the 77 litre tank

 

[cuteboy]

Try keeping your tank full or even abobe half.
When its low then it vanishes quicker,jence you lose what ever little there was.

 

[rick540]

There is a fuel consumption correction factor you can program into the OBC though I personally wouldn't mess with it.

Sticky sensors or the contacts getting coated with something are quite common these days (Something in the fuel) I find a dose of injector cleaner or a bottle of redex sorts it out for a month or two.

 

[Philip Foglar]

Well with that experience my Wife knows not to let the range to empty get less than 100km, I think rather fill up when it shows quarter remaining!!!

 

[Doomsdaya]

Well i have an E36 328i and it isnt quite as accurate as it says so I still rely on the old needle on the fuel gauge

When it has a hole in the exhaust, the range you get on the trip meter and what you actually drive is 2 different things :hammerhead:

It is just a mere guide and not an actual tool you can rely on

 

[Clownshoe]

Remember its a computer, so GIGO (Garbage in garbage out).

You should have a pretty good idea of of your speedo error (usually under reads unless you are running non-standard 22 inch mags). The error on your consumption will be related to that error. The car overestimates the distance you are covering. So your actual consumption is usually better than the computer.

If you have replaced the fuel level senders they may be in wrong and not reading correctly. There may be some calibration involved.

There is a margin of error in the computer distance usually. You should get 50km further than the DTE figure.

It doesn't hurt to run it dry once with a can of petrol in the boot. Take note of the ODO or better yet GPS distances that the DTE hits 0km, the petrol light comes on and when it dies. When I started out I had a E30 325i that used to run on fumes frequently and I got to know the car very well!! I once did a trip from Welkom to Grahamstown that I precicely timed to get the light to come on when I got into Grahamstown (picture James May on an economy run) It came on a few seconds after I stopped at the destination.imp:

So my experience with computers is quite good. The Jeep's is also quite accurate as with bigger wheels she is now spot on speed with the GPS.

If you have a bad input it will throw the computer. Input injector pulse width, speedo/ odo for distance and for calculating DTE it is probably some average consumption of the last 100km or something). Ofcourse if you have been driving Miss Daisy for a week and suddenly have to drive your pregnat wife to the hospital I wouldn't rely on the DTE.

I am not too sure but I think that DTE uses the fuel level sender and average consumption so changing road conditions, inclines and aggressive driving will make the fuel move around and it will overestimate the fuel in the tank.

 

[justintime]

i am not so proud of this but i drove for 35km after my range said _ _ _ but it did not read lower than 15km.. so i wanted to see how far it went on empty.. i did not run out of gas.. i just decide to stop my test because running out of gas in a drop top is just not cool