BMW E38 740i fuel gauge sending units

[mota702]

i have a 98 740i I just replaced the left and right fuel level sending units.The fuel gauge is still stuck all the way to empty with light on.Is there any fuses i can check?fuel tank was literally full when I replaced them if that matters.I need your guys input

[Mayorchuck]

There is no fuse. Is the float on able to move freely? Try unlocking your cluster and see if Test 6 is reading the fuel level on each side.

http://www.bimmerforums.com/forum/sh...-and-diagnosis

[xboss]

Those can get stuck on stuff going in. they were moving freely and floated up?

[mota702]

yea they move freely inside the tank and i cant check anything on my cluster.Pixels are blurry

[xboss]

Maybe a battery nap will reset them? Yeah, you def need to get the cluster working so you can see if they are sending data that way you can rule out the cluster gauge.

[mota702]

I tried a battery reset for like 10 mins that didnt work.Also I cant read anything on my cluster missing pixels

[xboss]

Right, you should fix the cluster

[Mayorchuck]

The two smaller gauge wires leaving the pump send the signal for the tank content to the cluster. One easy way to check it is to try another cluster. Maybe one of the guys out your way have a used one you can pop in for a few minutes to check it.

[Qsilver7]

Yeah...too bad you haven't got the cluster's pixels repaired. Doing TEST 6 would definitely give you an idea if the fuel level senders are sending data to the IKE (instrument cluster). And you need to do TEST 21 which is a reset procedure for the IKE when there is work done like you performed.

See the descriptions of TEST 6 and TEST 21 below for a brief explanation of the info they provide:

[mota702]

how do you do those tests on the cluster?

[Mayorchuck]

how do you do those tests on the cluster?

Huh? You said your pixels prevented you from doing so. The instructions are in the link I provided above.

[jjc034]

So I pulled the pump and sending unit after having the dreaded knocking sound in my tank followed by the whistle, in order to replace the white valve. When I put everything back in, my fuel level sensor wasn't working. I pulled everything again to double check and all wires are good and the float can move freely.

Ran test 21 to reset the gauge and now my quarter tank has dropped to nothing with the reserve light on. Test 6 shows 0 for right sending unit and works for the right.

I'm going to try a battery nap, but what are other people's suggestions if that doesn't work?

Sent from my SM-G930V using Tapatalk

[jjc034]

So I pulled the pump and sending unit after having the dreaded knocking sound in my tank followed by the whistle, in order to replace the white valve. When I put everything back in, my fuel level sensor wasn't working. I pulled everything again to double check and all wires are good and the float can move freely.

Ran test 21 to reset the gauge and now my quarter tank has dropped to nothing with the reserve light on. Test 6 shows 0 for right sending unit and works for the right.

I'm going to try a battery nap, but what are other people's suggestions if that doesn't work?

Sent from my SM-G930V using Tapatalk

Battery nap didn't work. Additionally, when I pulled the unit a plastic clip broke off, disconnecting the unit from the metal holder on the cap. It was original and car has 186k miles.

I zip tied in place and all wires look to be in good condition.

If I need to get a new sender I will, but prefer not to

Sent from my SM-G930V using Tapatalk

[bagodonuts]

Broke needle off mine (the part that makes contact with the lines )whilst replacing fuel pump...not sure how. Finding passenger side sendingunits on ebay for over $300. Ick. Anyone have luck building these or swapping the reading instrument from the cheaper driver side version. I'll probably head to a junkyard.