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1998 BMW 740iL Question: Fuel Tack Vacuum

 

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SCTom, Chapin, SC, October 07, 2010, 12:47
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This car has 465,000 miles and still rides like new. original fuel tank flexed and eventually ruptured into a leak. second tank has 0ver 200K miles and is doing the same thing. All valves and vents have been replaced. Only component left is the charcoal filter assy. Any suggestions and where is the charcoal filter located?

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  • Answer #1

    dandd October 07, 2010, 18:32
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     Master

    Most BMWs an Evaporative canister which has the charcoal and Leak detection pump as a unit. It is mounted very close to the fuel tank, that is covered by a metal shield.

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    Visitor, October 10, 2010, 10:38

    Thank you Dan. Before I tackle this job I want to be reasonably sure this will solve my problem. The fuel tank is pulling a vacuum when there is less than half a tank of fuel and popping out when the pressure is relieved. Check and Vent valves have been replaced in the last 6 weeks. I was told the only thing left it could be is a clogged Charcoal Filter. Again, the tank flexes and POPS at less than half a tank. Any other suggestions before I go after the filter ?
    Thank you -----------------Tom

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  • Answer #2

    Visitor, October 09, 2010, 18:54

    contact me tom at Timothycounts@att.net. I live in chapin also. Would like to meet to discuss common problems with our 740 il. Very coincidental.

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