Fuel gauge messed up...Fuel sending unit problem?

Hey guys. I was out tonight with a friend. We happened to be on a twisty road, and we decided to do some "spirited" driving. Checked the oil temp, and it was at operating temperatures, so offwe go. A good 2-3 min of a few twisty bits and corners. Then, my friend mentioned that he noticed the fuel guage was looking strange. I look at it and notice that the needle is all the way down, in the position it's at when the car is off. I had just filled up a few days ago, and had at least 150 more miles left in the tank.

I'm guessing that the fuel sending unit is acting up again (it had been replaced alerady under the previous owner)

Any thoughts? I'm not under warranty. If I am forced to take it to the stealer (which I pray to GOD I don't), how much do you htink it'll cost me? $200 +?

I think I may have to take it to the dealer because from this:
http://www.zvolution.com/documents/16/12/RA_16_12_000_Replacing_fuel_gauge_sensor_(Z3_unit_ sensor-pump_complete).pdf

it looks like there are two "special" BMW specific tools needed.

Should I try mixing some Techron fuel injector cleaner to the fuel tank? Like an ounce or 2? Or more? I'm not sure if this would help if its a fuel sending unit problem. It makes more sense if it is a fuel pump problem...Also, how much do I add to the fuel tank? Should I add the whole 20 oz when the tank is half filled?

All feedback is welcomed and greatly appreciated. Thanks

Reply » Fuel gauge messed up...Fuel sending unit problem?

Overfilling your gas tank can cause the fuel gauge to act whacky, as you describe. The only fix I know of is to replace it. Whether or not it's DIY depends on your skills.

Reply » Fuel gauge messed up...Fuel sending unit problem?

I never overfilled the gas tank.

I did however, drive the car for a little bit while it was in the "red zone" on the fuel gauge. Then I filled up a few days later. Supposedly this overheats the fuel pump because of lack of fuel to cool it? That's ridiculous, I don't understand why BMW would engineer the car to malfunction over time if the car is driven if there is not enogh ample fuel. While in the red zone, I'm sure theres at lesat 2-3 more gallons.

Reply » Fuel gauge messed up...Fuel sending unit problem?

I don't think driving in the red zone caused your fuel gauge problem. Maybe this link wil help. Click on the link and look under the middle column...Common problems. Scroll down to fuel gauge ...
http://www.waycoolinc.com/z3/essenti...xit/index.html

This is another link....http://www.mz3.net/articles/244.html

And another (scroll down to DWM's post (#4) and open the .pdf file) http://www.bimmerfest.com/forums/sho...ght=fuel+gauge

Reply » Fuel gauge messed up...Fuel sending unit problem?

Quote:

Thanks for the links, the first one especially brought me hope. I went and tried it in the order as follows (as they clarified)

: Car off
: pull fuse 31
: car starts
: car off again
: replace fuse 31
: start car and check fuel gauge (no luck)
: car off
: pull fuse 23
: start car
: car off again
: replace fuse 23
: start car and check fuel gauge (yahoo - it works)

Unfortunately, this did not work...

I am hoping I do not need to take it to the dealer. I really don't want to...

Reply » Fuel gauge messed up...Fuel sending unit problem?

I have had this problem with your car when it was still under warranty. Took it to the dealership and they replaced the sending unit. I guess you are due for another one?

I think it's a cheap part and is located behind the passenger seat. (The carpet behind the seat is already cut, so it should be a peice of cake to replace it

)

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