Fuel Tank

[Autotek]

Hi! need some help.I have a 1992 525i and the fuel take collapsed in like it had a vacume pulled on it.I changed the tank and gas cap and it happened again.It broke the fuel level sender both times.Does this system vent out of the vacume canister?any help would be good.Thanks Art ghead

[BeelZibub]

Originally posted by Autotek@Feb 23 2005, 01:51 AM
Hi! need some help.I have a 1992 525i and the fuel take collapsed in like it had a vacume pulled on it.I changed the tank and gas cap and it happened again.It broke the fuel level sender both times.Does this system vent out of the vacume canister?any help would be good.Thanks Art ghead

[snapback]297319[/snapback]

Ouch!!! People don't believe me when I say that a cars fuel pump can actually create a vacuum strong enough to collapse the fuel tank and therefore they should make sure the tank breathers are clear.

Sorry I can't help you with your specific problem, but now I can at least point scathing co-workers and friends at this link to save me arguing for ages about it.

I will however ask a friend of mine if he knows of an answer for you.

[billB]

Autotek to our froum

Yes it does. Sounds like a fuel tank ventilation problem. Charcoal canister helps your intake to suck up fuel pollution through a purge valve. When your fuel tank approaches empty, a vacuum is created so air displaces the gas through the purge valve/manifold/vent. Simple empty space filled by air/displacement for burned fuel. Seals in the purge valve act as pressure equalizer (full tank in the Sahara desert) and vacuum (empty tanks) equalizer (diaphragms/breathers etc) Charcoal takes care of filtration, thus, charcoal Canister. TO make things better or worse this system has a return line to the tank; so imagine what effect all this moisture/dirt-accumulating over time- can do to to your seals/fuel pump/fuel filter rendering ineffective ventilation. This can be witnessed by removing the fuel tank cap-air rushes into the tank/suction; and out of the tank/pressure. A constricted canister vent hose MAY produce similar results. But Collapsed Tank? This was some vacuum!
Regards
billb

[d3ity]

Yet ANOTHER reason why its a bad idea for me to play...hey its not QUITE at the E yet.