Removal of expansion tank in BOOT!!!!

[anton]

Hi all,

planning a mega sound quality installation,
in my e30 325i 1989 (november reg)

my boot is fitted with a tank, this sits behind the rear seat.
According to someone i spoke to, this is merely an expansion tank, so for instance incase of massive collision, the fuel moves over into the expansion tank instead of expanding...

think is... i need space for my sound... and so many e30's dont have this tank anyway.... and many of the newer bmws dont have this at all..

so i feel i can do away with it..


OPINIONS please??

and possibility recommendations of removal and blanking off pipe?

regards
Anton

[Ant]

sounds like you may have the long range fuel tank there Anton, post a pic up dude !

[anton]

hmmm..my etk/epc/tis dvd's arrived yesterday... currently searching for this part on it..
gives graphical view of how its connected and such.

Anton

[ed325i]

[anton]

howsit. cant quite work out if i can actually remove this or not.
some say its a secondary fuel tank... others say its merely an expansion tank for safety purposes?

dunno...
leaving it in is suppose the safest.. but with a sound installation on its way and a rear strut bar.. makes
things very difficuly.

anton

[Simon]

Would be pretty sure it's the long range tank, does your fuel guage have a small white block where the needle reads full?

[smithy318i]

it should be pretty easy to remove the tank.

you will need to buy a standard filler pipe to replace the one you have. then you can sell the long range tank to someone.

[anton]

hi guys,
ok this is the weird thing... today i removed the trim panel which covers the "expansion tank" or long range fuel tank..

the weird thing is, it has a sender-unit, when removing the plug which has 2 x brown wire/green stripe wires..
the fuel gauge doesnt work...

went to go fill-up fuel... and afterwards knocked on the "expansion tank" sounds very hollow.. dead empty...

also by looking at the diagram above, no.3 is the sender unit....

im in two minds about removing this thing, it'd make my life MUCH easier when i eventually do my sound install.

any suggestions? cant seem to work it out.. if it is infact an expansion tank, why would it have a sender unit?

want to know how many litres go into the tanks of some of the zoners?

i think its 4.8litres=1gallon.. not sure...

this would help me... my tank seems to take around 15gallons of fuel.. (converted it) takes almost 70litres of fuel.
this is when "empty" and filling up.. though reserve light isnt on yet...

look if its an expansion tank,, then its a safety thing right? like if the car get rolled etc... then the fuel has "somewhere" to go, instead of a fire risk...

doesnt seem to be a long range tank as there doesnt seem to be any fuel in there..
also, how would the fuel get in there, keep in mind the only place for the petrol to go into is at the pipe at the BOTTOM of the tank...

really confused at this stage...

getting a regular filler neck and installing it and taking the whole lot out is i suppose an option.. but why is this tank there in the first place... and why does it have a "sender unit". ????

any ideas?anyone?

could it perhaps be because here in south africa we have a hotter climate than some other places, so its safety?

if its merely an expansion tank, then why on earth is the filler neck a Y pipe?

cheers
Anton

[Simon]

Definitely a long range fuel tank, and the fact you live in SA confirms that.

Filling the long range tank is also a total pain in the arse, the fuel trigger will click, but you can carry on brimming the tank for quite a while until it is actually full.

[anton]

hi there,
ok im confused even more now...
here in south africa we are spoilt, we have petrol pump attendants. i.e u dont fill your own car..

anyways, when i experimented today, i heard the pump "click" thereafter..maybe 3 - 4 litres extra fuel went in..

infact.. it got overfilled.. seriously worried me.. as my car left a trail of fuel on the road for a few metres..
when i stopped and inspected.. i found that the filler cap's rubber seal obviously doesnt seal like it used to, when removing the cap i could see the fuel... laying there.. so maybe 300 - 500ml of fuel spilled out thru the leaky fuel cap..
when i opened the boot.. gave the "long range tank" a few knocks.. sounds dead empty?

what gives???

could i have a blockage in the y pipe stopping fuel from going into the secondary tank???

[Martinaston]

The expansion tank you keep refering to is up in the wheel arch next to the filler cap, have a look at the link.
You should have a ventilation hose that releases the air when filling. (number 5, could be blocked)

http://www.realoem.com/bmw/showparts.do ... g=16&fg=10

If you have a leak on the seal of the pump in the lower tank it will gradualy drain the long range tank until the fuel level reaches the height of the leak, that could be expensive if the extra tank holds a couple of gallon.

[anton]

hi there
so you mean, the possiblility of actually having some kinda blockage that is stopping the long range tank filling up is quite real...

going over to a bmw dealership tomorrow to enquire... if anything like this can/has happened then i am sure they will have a fix of sorts...

like i said, i filled her up earlier today and it appears that the long-range tank didnt get filled at all.
no. 5 on the diagram is the hose, maybe somethings up there, is no.5 the hose where the fuel actually enteres into the long range tank... because lying under the vehicle, the Y filler neck splits into the entry point at the bottom of the long range tank.

ok.. my scoring is as follows:

possibility of it being long range tank = 8.5
possibility of it being mereley expansion tank = 1
out of 10.

i will fire up my bmw epc/etk software and look at some diagrams...

well... my vehicles owner manual suggests the fuel capacity of being "approximately 75" litres

yet when on empty, i fill up and cant seem to get any more than 66litres +- of fuel in it.

my experience tells me.. that when a owners manual says.. tank capacity 45liters for example normally
this means one could get perhaps close to 48 or 49litres of fuel into it..
so, 65 - 66litres of fuel, this means im "missing" 10 - 15litres...

maybe the previous owner was BLONDE, and a mechanic asked her about the tank..
perhaps she wouldve said.. PLEASE DISCONNECT THE SECOND TANK AS I WANT TO SAVE PETROL AS ITS TOO EXPENSIVE.. AND THE CAR WILL USE LESS PETROL WHICH WILL BE CHEAPER...

cheers
Anton

[Martinaston]

As standard the two tanks that go under the seat are 55L or a 63L and the measure (i assume) does not include the filler pipe so you can normaly get a bit more in.

Number 5 is the breather pipe to let the air out while it fills from the bottom.

If you can't get more than 66L in then i'd say check the breather hose is not kinked by the boot lining or someting, If its there at all

If you remove the tank you are aware you'll have a hole in the floor of the boot

[anton]

i do some panel work etc.. fibreglassing or even welding it shut is no problem for me..

the boot is anyway going to get re-sprayed...

slight slight surface rust here and there, so i'll be flatting and sprayying soon....

i compete in iasca sound quality competitions... my beemer is going to get "the treatment" soon.

its currently got a new nakamichi cd400 headunit, got a jlaudio e4300 amplifier waiting for it and a jl audio 10w1v2 subwoofer waiting...

the soundproofing from secondskin audio (2gallons of spectrum, 40sq ft of damplifier) is on its way from USA to me as we speak/type.

meanwhile im busy respraying my pickup, so once the pickup is on the road again.. then i can play plenty at leisure with the beemer.

Anton

[jog5000]

By the way Anton, where in SA are you? I'm down in Cape Town....

[anton]

im down in cape town too!! durbanville to be exact. where about are you?

regards
Anton