Poor Mileage... Need Advise

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taggnas

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Dear Sifu,I drive a 1999 E46 6 cylinder 320i. Lately I have been experiencing poor mileage per full tank. I now clock slightly less than 400 km and the light comes on at around 330 - 350 km. I have been doing lots of city driving here in KL mostly home-work-home. In the same conditions, I used to be able to clock at least 550 km but not anymore. Was wondering if anyone had faced this similar problem and that you if you could share what you did to get that fixed and how much. I plan to take my car in for a check up at my mechanic in USJ over the weekend but am hoping for some advise before then. Thanks guys.
 
there could be several possibilities incl a bunch of faulty sensor. have a good mechanic perform a thorough check. light on at 350kms is bad; my old E46 330i averaged 460kms.
 
yeap as mizhan mentioned could be the float sensor, or could be the delivery pipe that got stuck. e46 tank has 2 sections, left and right. Once right is almost down, the vacuum will draw from the left section. There is away to test, use the OBC hidden functions :

Instructions to access the hidden OBC functions:
1. Hold Trip Reset while turning ignition key to on position
2. OBC should show "Test"
3. Use Trip Reset to select function 19.0 that unlocks all the features
3. Wait for display to show "Off"
4. Depress Trip Reset for 1/4 second and release it
5. With no delay press Trip Reset several times to select one of the following function s

BMW E46 On-Board [COLOR=blue! important][COLOR=blue! important]Computer[/COLOR][/COLOR] (OBC) Hidden Codes
Example description
1 Car Engine and cluster data
1.0 46nnn Chassis nr/VIN serial number (last 5 digits)
1.1 4nnn K-number
1.2 690236 Cluster Part #
1.3 045210 Coding (04)/diagnosis (52)/bus index (10)
1.4 1200 Week (12)/year of manufacture (2000)
1.5 09_160 Hardware (09) and software # (16.0) of cluster
1.6 Not used
1.7 04__44 CAN-version (04) KI-revision index (44)
2 (test) Cluster System Test - Activates the gauge drivers,
indicators and LEDs to confirm function
3 SI Data
3.0 1098 Used fuel in liters since last SI (Service Inspection)
3.1 0231 Periodic inspection days; elapsed days (since last SI)
4 Momentary Consumption
4.0 0145+ Instant [COLOR=blue! important][COLOR=blue! important]fuel [COLOR=blue! important]consumption[/COLOR][/COLOR][/COLOR] - 0145=14.5 liters/100km
4.1 0018 Instant fuel consumption - 0018=1.8 l/Hour
5 Distance Gone Consumption
5.0 082 Average mileage; 082=8.2 liters/100km
5.1 0536 Calc. km to refuel (momentary distance to go)
6 Fuel Level sensor inputs in liters
6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters
6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters
6.2 0442+ Indicated value (44.2) and tank phase
7 Temperature and Speed
7.0 021+ [COLOR=blue! important][COLOR=blue! important]Coolant[/COLOR][/COLOR]/Engine temperature (2.1C)
7.1 130 Ambient/Outside temperature - chg met 5 pts. 125/130/135
7.2 + Engine speed / Current RPMs 1/min
7.3 + Vehicle speed / Current Speed in km/hour
8 Input value in HEX form
8.0 1d0+ System voltage ADC-Value Hex code
8.1 26C33C+ ADC Values HG left/HG right
8.2 0000 ADC Value brake degradation sensor (000=o.k.)
8.3 18C ADC Value outside temperature
9 Battery
9.0 140 Battery Voltage - 140 = UB 14.0v
9.1 242013+?
9.2 074_78+?
9.3 0011+?
10 Not used
11 Not used
12 Not used
13 GonG Gong Test
14 Not used
15 Status cluster I/O-ports (bit codes) 0=low; 1=high
1st-belt contact, seat belt fastened=0; 2) ignition lock contact, key inserted=0; 3) door contact, door open=0; 4) clock button pressed=0; 5) SI reset=0, for reset=0; 6) EGS [COLOR=blue! important][COLOR=blue! important]transmission[/COLOR][/COLOR] failure=0
Status Digital Outputs (bits) 0=inactive, 1=active
1) Gong output; 2) Brake warning [COLOR=blue! important][COLOR=blue! important]lamp[/COLOR][/COLOR]; 3) Low fuel warning lamp; 4) EGA lamp; 5) seat belt lamp; 6) manipulation dot
16 Not used
17 Not used
18 Not used
19 Lock Status; unlocks functions in range 3-18
19.0 L-On/L-Off Unlock: press button when "L-Off"
20 Not used
21 Software Reset; reset OBC settings
00 End of test

select 6.0 , 6.1 and 6.2 to see your average and if ur meter is reading it right.

Hope this helps :)
 
Hi Ice duke,

I think I'm having a similar issue with FC....think its bad...

Just wanted to ask u. Do you mean that the values you stated here should be the correct readings? If not then there's a problem? Tx

6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters
6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters
6.2 0442+ Indicated value (44.2) and tank phase
 
City drive if your place is hilly and each trip is around 5km you will get very poor FC ie 350km per tank. It happened to me with my N42B20 as I only drive from home to work around Mont Kiara plus 1 TT at Sunway on friday night, I used up my full tank RM100 with only 360km.

However after LIQUI MOLY Jet Clean, New injectors coils, New fresh Engine Oil, Fuel Filter and Spark Plugs my worse FC with the same distance has increased by 30km Hahaha means 390km but on highway, KL Kuantan KL 530km now I can get 620km
 
Get a diagnosis done and usually you should be able to pin-point the culprit.
 
wingzee;795030 said:
Get a diagnosis done and usually you should be able to pin-point the culprit.

Sometime computer cant tell the problems as like my case.
 
Mine on a town drive short distance (maybe around 7-8km per drive) with RM50 Ron95 i get only ard 150km or so... the warning light comes on ard 130km. Now I trying full tank to see if there's a difference....325...
 
integramania;795064 said:
Mine on a town drive short distance (maybe around 7-8km per drive) with RM50 Ron95 i get only ard 150km or so... the warning light comes on ard 130km. Now I trying full tank to see if there's a difference....325...

Full tank for our ride costs about RM110 or so it means that you're only getting less than 350km per full tank town driving? Heavy-footed is it? :p
 
wingzee;795076 said:
Full tank for our ride costs about RM110 or so it means that you're only getting less than 350km per full tank town driving? Heavy-footed is it? :p

Its not regard to how heavy our foot bro as our car burn more fuel when engine did'nt operate at optimal temp. :) Worse if below 10km per trip

Last the week before Xmas, I tried to warm up my engine to 90c before I drive, there an improvement of 40km per RM100, please give this a try ya.
 
Bro wingzee I drive like old man la.....hahaha....

Bro anaksarawak. Yeah that's what I undertsnad also....drive les...burn faster....You have temp meter to check?
 
integramania;794993 said:
Hi Ice duke,

I think I'm having a similar issue with FC....think its bad...

Bro what brand petrol you are using ? My old junk also having the bad FC lately on Petronas ron95, so i try switch to Esso ron95 and now i get better FC. I am not sure why..maybe the Esso petrol additive was better to my old junk now i guess..
 
Alex5522;795104 said:
Bro what brand petrol you are using ? My old junk also having the bad FC lately on Petronas ron95, so i try switch to Esso ron95 and now i get better FC. I am not sure why..maybe the Esso petrol additive was better to my old junk now i guess..

Agree with you Alex5522, I was with Shell then Petronas both are not as good as BHP or CALTEX or ESSO. There are few or no ESSO around KL now.

Bro,

To check the coolant temp follow this video coolant is #7 [video=youtube;ImCUQjmMhfM]http://www.youtube.com/watch?v=ImCUQjmMhfM[/video]

good luck
 
anaksarawak;795119 said:
Agree with you Alex5522, I was with Shell then Petronas both are not as good as BHP or CALTEX or ESSO. There are few or no ESSO around KL now.

Bro,

To check the coolant temp follow this video coolant is #7 [video=youtube;ImCUQjmMhfM]http://www.youtube.com/watch?v=ImCUQjmMhfM[/video]

good luck

My Seremban to Johor and Puchong to Sungai Petani drive using shell petrol RM1.90. FC is RM0.1508/km. I just changed alternator from 90A to 120A. Now 90A keep as spare.
 
tweiboon;795179 said:
My Seremban to Johor and Puchong to Sungai Petani drive using shell petrol RM1.90. FC is RM0.1508/km. I just changed alternator from 90A to 120A. Now 90A keep as spare.

Replacing or upgrading to higher rate alternator can save fuel?? Cool share bro
 
anaksarawak;795186 said:
Replacing or upgrading to higher rate alternator can save fuel?? Cool share bro


For this i really dont know what is the logic behind. Before change the alternator my FC is RM0.18 to RM0.20 for the mentioned above drive. Before i changed the alternator, my foreman said is will have better FC if change to bigger alternator due to i am using 90A. I though my 90A having problem but infact the 90A alternator is still working fine. Due to Malaysia too hot causing use must on air cond will cause less charges to battery and shorten the battery life.
 
tweiboon;795191 said:
For this i really dont know what is the logic behind. Before change the alternator my FC is RM0.18 to RM0.20 for the mentioned above drive. Before i changed the alternator, my foreman said is will have better FC if change to bigger alternator due to i am using 90A. I though my 90A having problem but infact the 90A alternator is still working fine. Due to Malaysia too hot causing use must on air cond will cause less charges to battery and shorten the battery life.


Logic is fair!
 
I'm using Esso....RON95...

This FC dilemma has been plaguing me on all my cars I ever owned...lol...
 
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