1999 BMW 540i Tech problems

KICKINDIRT35

MEMBER
1999 BMW 540I
V8
2WD
AUTOMATIC
98,507 MILES

Near the fuel tank, I get a humming noise and as soon as the noise stops it skips. Only does it from time to time, at a crusing speed. No noise on take off. In the beginning had a code 01 dmtl, replaced evap. Canister and pump and fuel pump, fixed code still makes noise and skips. Can anyone help?

7 Replies

DOCHAGERTY

MECHANIC
9,601 POSTS

Have you tried replacing he fuel pump relay?

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Tuesday, March 10th, 2009 AT 7:34 AM

KICKINDIRT35

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4 POSTS

Yes, That was stated. Thank you for your help.

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Tuesday, March 10th, 2009 AT 10:26 AM

DOCHAGERTY

MECHANIC
9,601 POSTS

I must have missed where you stated the fuel pump relay was replaced. Was the main relay replaced too?

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Tuesday, March 10th, 2009 AT 8:20 PM

KICKINDIRT35

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4 POSTS

Yes, We have replaced and tried many things. Nothing fixes it. Any more ideas? Thanks for your help.

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Wednesday, March 11th, 2009 AT 12:43 PM

DOCHAGERTY

MECHANIC
9,601 POSTS

When you say it skips, do you mean the motor has a misfire or it intermittently stops running for a brief moment, like the ignition was cycled off and then back on again. Has the dealer been involved?

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Wednesday, March 11th, 2009 AT 1:28 PM

KICKINDIRT35

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4 POSTS

It misfires. No dealer. Thanks

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Thursday, March 12th, 2009 AT 11:40 AM

DOCHAGERTY

MECHANIC
9,601 POSTS

OK so it's an ignition misfire and not fuel starvation. Have you monitored the main relay, it could be momentarily dropping out. If it is, the electrical portion of the ignition switch has been known to cause issues. Part # 61-32-6-901-962

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Thursday, March 12th, 2009 AT 12:32 PM