2nd fuel tank problem. Need help!

[fashraf]

Dear all otai(s) and sifu(s),My ride (e46 2.0 2002)have now a new problem. The second fuel tank didnt flow the fuel properly to the 1st tank (where the pump is located).My mechanics advise me to replace the connecting tube and I have replace it (cost me rm500++). But the problem still there!Now I have to always to full up the tank whenever the indicator shows 1/2 tank... very irritating... Hope you guys can help with advice....:argh:

 

[jarance]

try this webpage.

http://jbbeach.com/files/documents/bmw323ci/160-3_Fuel_Pumps_and_Senders.pdf

Apparently, there is another siphon tube inside the tank.

Do check it when the tank is near empty or else you gonna to lose alot of petrol when you open the left and right fuel sender cover.

PS.. DO NOT SMOKE WHILE WORKING.

 

[fashraf]

Yup, that exactly my mechanic change.. The siphon tube.... Still prob exist. Also just change the fuel filter... Another rm170.... Prob still there...

 

[fashraf]

Could it be the fuel pump that is weak enough to "suck" the petrol from the 2nd tank?

 

[jarance]

Yup, that exactly my mechanic change.. The siphon tube.... Still prob exist. Also just change the fuel filter... Another rm170.... Prob still there...

did he use the right type of filter cos the fuel filter have an pressure regulator.

 

[jarance]

Could it be the fuel pump that is weak enough to "suck" the petrol from the 2nd tank?

The fuel sender suck from one place only.

 

[fashraf]

did he use the right type of filter cos the fuel filter have an pressure regulator.

Yup he changed the one with the pressure regulator...

 

[jarance]

did you change the sucking jetpump. see item 3 below.

If you did, did he install the check valve properly at the item 5. The check valve position is important. If it is reverse, the jetpump would not work at all.

This item is used for equalizing the petrol from the left side to the right side.



Fuel pump and fuel level sensor - BMW parts catalog

 

[jarance]

Here is a clearer picture of the check valve.

 

[fashraf]

did you change the sucking jetpump. see item 3 below.

If you did, did he install the check valve properly at the item 5. The check valve position is important. If it is reverse, the jetpump would not work at all.

This item is used for equalizing the petrol from the left side to the right side.



Fuel pump and fuel level sensor - BMW parts catalog

hi bro jarance, thanks for so much info so far. but still my udm prob still there...
the jet pump seems to come together with the siphon tube if i am not mistaken. that mean my mech have changed it in a set. item 5 is just an o-ring is it? how to make sure it is not up-side-down?

 

[fashraf]

will try to upload the pic of the part changed...

 

[sopian]

last time my E39 also got this problem... my mechanic replaced fuel pump only and problem solved.. but i don't know about yours... pump is running but not strong enough to suck fuel..

 

[fashraf]

bro sopian, I guess u were right. Just got my fuel pump replaced and now back roaring! The original fuel pump seems to be not strong enough to suck the pump from the 2nd tank.

Anyway, thanks bro Jarance too for the effort of helping. But I gain a lot of knowledge from the info posted by you!

 

[jarance]

bro sopian, I guess u were right. Just got my fuel pump replaced and now back roaring! The original fuel pump seems to be not strong enough to suck the pump from the 2nd tank.

Anyway, thanks bro Jarance too for the effort of helping. But I gain a lot of knowledge from the info posted by you!

Glad to hear the problem have been resolved. :rock:

btw, you never mentioned that your car could not start as well.

 

[fashraf]

bro jarance,

my car still cam start as normal when the problem happened. My symptom is that the fuel indicator shows 1/4 of tank when the engine stopped and after that cannot start (kena 3 time at the highway... sigh...).

 

[jarance]

bro jarance,

my car still cam start as normal when the problem happened. My symptom is that the fuel indicator shows 1/4 of tank when the engine stopped and after that cannot start (kena 3 time at the highway... sigh...).

Your problem could have started from the time that you have allow the pump to run "dry".

Fuel pump are prone to damage when there is no petrol..

 

[fashraf]

owh..?? really??...:stoned: then how to prevent this? must always top up fuel before the fuel indicator pop out is it? :stoned:

 

[jarance]

owh..?? really??...:stoned: then how to prevent this? must always top up fuel before the fuel indicator pop out is it? :stoned:

I usually look for my favorite petrol station ASAP when the light pop out..

For E46, when the light pop out, you have about 70km to go before you run out of petrol.