E36 - fuel gauge problem

[Russie]

This happened to my car just now, the fuel gauge suddenly dropped all the way down to "empty" level with the warning light on. I still have 3/4 tank of petrol coz just pumped yesterday. The car was able to drive back with no problem. When reached home, I did the so called "test" by press and hold on the reset button and turn the key to "on", all the gauges were able to move. The question is... could it be the fuel gauge on the dashboard? or the float sensor in the petrol tank? Anybody faced this problem b4? My car is E36 318i (M43). Appreciate some feedback.Thanks

 

[sesat88]

Most likely your fuel sender unit is acting up. Either disconnected, broken or the whole unit is have issue. Go get your mechanic to check it out.

 

[Strider]

most probably a disconnected wire at the fuel pump.

 

[Russie]

Once I got back home, I immediately check for leakages...none. No fuel smell either. So probably the fuel sender problem coz I went through some uneven roads last 2 days. Will be sending in the car for a thorough check tomorrow.

 

[Strider]

Russie,

I understand your first post and i believed sesat also the same. Your fuel tank still got fuel but the meter telling you otherwise. I had experienced this before with my E36. My mechanic straight forward knew that something wrong inside the tank. Take out the pump and immediately saw one of the wire disconnected (think the soldering part not that good). Connect it again and walla, till today, i'm a happy man. Don't worry, it is a small matter only, but need your time at least 1 hour. Good luck

 

[jarance]

There are two fuel sender for an e36. It located under the passenger seat.

1. Remove the seat.
2. Remove the black oval cover.
3. Left side got one connector.
4. Right side got two connectors. One black and one white. (one for pump and one for fuel sender)
5. Compare color with left connector with right connector. If it black color, then the right connector for fuel sender will also be black.
6. Disconnect both connector and measure the resistance. It should be around
10 ohms to 130 ohms. The one with open circuit is the one with broken wire.

Based on my experience, it usually happen on the one with the fuel pump.
This is because the fuel pump tends to pull the whole unit down when you go
over a speed bump. Look out for the diamond shape rubber damper. It is most
likely to be broken.

You can solder the wire back with a soldering gun.

1. To remove the fuel sender and pump, you will need a small hammer and a flat bar.
Use the hammer and flat bar to tap the cover open unless you have the special tool
to hold the cover.

2. You will also need to clean the area before opening to prevent the dust from going
into the petrol tank. Also prepare a small bottle to collect the petrol when you
remove the two hoses. (One for engine and one for recirculation)

Note: try not to open the cover if the fuel tank is full as it tends to overflow and you will lose alot of petrol. You can estimate the tank to be half after you fill to full and drive a estimate of 200 KM to bring the tank to half.

Use a clean cloth to cover the opening when you have remove the fuel
pump and sender.


CAUTION: DO NOT SMOKE WHILE WORKING ON THIS PUMP..

 

[Russie]

There are two fuel sender for an e36. It located under the passenger seat.

1. Remove the seat.
2. Remove the black oval cover.
3. Left side got one connector.
4. Right side got two connectors. One black and one white. (one for pump and one for fuel sender)
5. Compare color with left connector with right connector. If it black color, then the right connector for fuel sender will also be black.
6. Disconnect both connector and measure the resistance. It should be around
10 ohms to 130 ohms. The one with open circuit is the one with broken wire.

Based on my experience, it usually happen on the one with the fuel pump.
This is because the fuel pump tends to pull the whole unit down when you go
over a speed bump. Look out for the diamond shape rubber damper. It is most
likely to be broken.

You can solder the wire back with a soldering gun.

1. To remove the fuel sender and pump, you will need a small hammer and a flat bar.
Use the hammer and flat bar to tap the cover open unless you have the special tool
to hold the cover.

2. You will also need to clean the area before opening to prevent the dust from going
into the petrol tank. Also prepare a small bottle to collect the petrol when you
remove the two hoses. (One for engine and one for recirculation)

Note: try not to open the cover if the fuel tank is full as it tends to overflow and you will lose alot of petrol. You can estimate the tank to be half after you fill to full and drive a estimate of 200 KM to bring the tank to half.

Use a clean cloth to cover the opening when you have remove the fuel
pump and sender.


CAUTION: DO NOT SMOKE WHILE WORKING ON THIS PUMP..

Unker Jarance, are you by any chance in Klang today? If yes, maybe you can help me to check or even "solve" this problem? If u r ok with this lor... My office is in Jalan Kapar (near Tabung Haji), do let me know...thanks

 

[dannybaba13]

agreed,,,memang sini byk sifub terror and genius bravo rgards tqvm dan

 

[anaksarawak]

I have the same problem before and BMWong at Cheras solved the problem for me within an hour. It is the sender's wire or itself has failed

 

[jarance]

Unker Jarance, are you by any chance in Klang today? If yes, maybe you can help me to check or even "solve" this problem? If u r ok with this lor... My office is in Jalan Kapar (near Tabung Haji), do let me know...thanks

Sorry, presently in PD. WIll be back on Sat evening. Can help you look at it on Sunday afternoon or late morning. My house located in Eng Ann.

 

[Russie]

Sorry, presently in PD. WIll be back on Sat evening. Can help you look at it on Sunday afternoon or late morning. My house located in Eng Ann.

Oh, I will try to visit the mechanic later and see if it can be fixed or not. If I need your help, then I would contact u on Saturday or Sunday morning. Care to PM me your contact number? U r in Tmn Eng Ann? Somewhere near the Alliance Bank is it?

Thanks for your kind assistance too cheers~

 

[Russie]

Sorry, presently in PD. WIll be back on Sat evening. Can help you look at it on Sunday afternoon or late morning. My house located in Eng Ann.

Jarance, I got your PM, thanks. But just wanna update you guys here, I managed to fix that problem. Eventually, it is the broke fuel sender wire on the right hand side fuel pump. Sent it to the mechanic, he did some soldering and fixed back the unit...now it is back in working order. Total damage for this....RM30 (labour for the soldering works).

Thanks to everyone who contributed input points on this issue.

Cheers

 

[jarance]

Good to hear that you have got the problem fixed.

Did you by any chance check the rubber damper that is holding up the fuel pump.

 

[Russie]

Good to hear that you have got the problem fixed.

Did you by any chance check the rubber damper that is holding up the fuel pump.

Yes, checked the rubber damper and it is still in good shape. The fuel sender wire broke from inside the fuel pump itself.

But now, I notice there's some very minute movement in the fuel gauge needle. Is this normal?

 

[Russie]

Today evening, on my way back home, I think my fuel sender wire disconnected again coz the fuel gauge is showing empty and the empty light is on too. This time, could it possibly be the other fuel sender wire on the left side fuel pump? The last time I got it fixed, was the fuel sender wire on the right fuel pump. Hope it's nothing major or serious (keeping my fingers crossed). Will be sending in for repair soon.

Any E36 faced this problem before? I mean having this problem twice.

Thanks

 

[jarance]

Just remove the connector and measure the resistance. The one with resistance more than 500 ohms will be one with disconnect cable.

yes it will happen again especially you go over a bump. Take note that the original cable is just enough. I have repaired it by changing the cable and giving an extra slag for the "bump".

 

[Russie]

Thanks for the tips Jarance. I will ask if the mechanic can modify the cable, if he can't, will just stick to the original length

 

[jarance]

Thanks for the tips Jarance. I will ask if the mechanic can modify the cable, if he can't, will just stick to the original length

make sure that the plastic insulation is resistance to petrol if you intend to retrofit them. eg.. silicon rubber.

 

[automech]

Hi there, new here. I have similar problem with my gauge last 2 months ago and it freaks me out. I took out the floorboard in the trunk area, opened up the little rubber cover, and unplugged the sensor. Shorting the fuel gauge wire to ground gave me a full tank reading, which I hadn't seen in many years, so I realized everything else is good but my sending unit must not be working right.

 

[Russie]

Got the fuel sender wire fixed. Eventually, it was the same wire which broke again, so my mechanic soldered it back and it's functioning again.

Cost of repair this time: FOC

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