Fuel gauge acting funny

[red96z3]

Car ~ 1996 BMW Z3 roadster

This morning on the way to work I saw the fuel gauge simply drop to E; actually below E like it just quit working and the low fuel lamp was lit. I know it's not empty as I just filled it up yesterday. After getting to work I shut the engine off then turned the key back on. Fuel gauge read F as it should. On the way home tonight, I gauge read normal (F) for about 10 seconds then dropped to E again. I stopped a couple of times on the way home and it did the same thing each time. Starting the car, the gauge reads correctly but after maybe 10-15 seconds of driving, it goes back to E.

I wouldn't think a fuze as it'd either be working or not. Everything else seems to be working - dash lights, speedo, tach, temp, interior lamps, wipers, turn signals, etc. Any ideas?

Appreciate it.
Dale

[djzeroflau]

You could check if got current going to the fuel pump, and if theres current going to the fuel gauge, if not check the relay (i doubt it could be that) but just check it. Sometimes the soloutions to problems like this are so simple.

sorry i couldn't help much

[killeen_john]

Take it to the dealership... there is a TSB #160101 or #160201 regarding faulty fuel sender that had to be performed on both my 96' Z3 and my 00' M Roadster. The dealer will need to replace the fuel pump with a revised unit that has gold electrical connectors that will not corrode. To gain access to the fuel pump, the dealer will cut an opening in the carpet behind the passenger's seat near the center console.

[DannyCop]

Originally Posted by killeen_john

Take it to the dealership... there is a TSB #160101 or #160201 regarding faulty fuel sender that had to be performed on both my 96' Z3 and my 00' M Roadster. The dealer will need to replace the fuel pump with a revised unit that has gold electrical connectors that will not corrode. To gain access to the fuel pump, the dealer will cut an opening in the carpet behind the passenger's seat near the center console.

I just bought a 98 Z3 and when I filled it up the fuel gauge did the same thing. I suppose im haveing the same trouble?

Dan

[fastcompany166]

Originally Posted by DannyCop

I just bought a 98 Z3 and when I filled it up the fuel gauge did the same thing. I suppose im haveing the same trouble?

Dan

Having the dealership look at it is probably a good idea, as the TSB mentioned above also addresses issues that can be caused by using reformulated gasoline. If you live in one of the metro areas where reformed fuel is used, this could also be an issue. The dealer has a fix.

[ctapia1]

Another Gas Pump Issue:

I have a 2002 2.5 z3 and I was just driving with the empty fuel red light on so I decided to fill the car with gas. As I was fueling the car, it automatically stopped at 7 gallons. I found it strange since it has a 13 gallon capacity. My car was on empty. I just reached about 200 miles on a full tank of gas and was on empty. So, I tried to pump more gas but it stopped immediately. I tried again and slowly squeezed the gas trigger and noticed that some fuel spilled out like when the gas tank is full.

How could the gas tank be full with 7 gallons? I turned on the car and noticed the gas guage reading 2/3 full. Could something be stuck inside? Could the flow of gas have been too much that it didn't travel all the way down the tank?

Anybody here of this?

[fastcompany166]

Check the TSB #s posted earlier in the thread with your dealer. Malfunctioning sending unit could deliver the symptoms you're having.

Bob

[BAVARIANM]

It's the sending unit. The access is already there in the carpet. You can change it yourself, but make sure you're below a quarter tank of fuel.

[djzeroflau]

Working with Gm's i've noticed that cars that come in with that problem its usually a vent valve. When the vapors are blocked before getting to the tank. i've seen a Wave that came in and it was a spider web stuck in te vent hole. But back the Bmws. it could be the sending unit. again as another post said take it to Bmw and get them to read up on the TSB.

[ctapia1]

So, I made an appointment with the BMW Dealership and told them exactly what happened. One service tech said it could be the gas pump and it's nozzle since he's encountered that before. He mentioned the way the way the gas pump gun works so I looked it up on howstuffworks.com (along with the gas tank).

Another tech said it could be the sending unit but neither of them could agree that this could be the solution to that particular problem.

I think it was the way the gas was being pumped and I don't think I'll have them replace it if they need to cut the carpet. I talked to a couple other people with a BMW and other manufacturers and they've had a similar infrequent incident like mine.

Thanks Everyone