On my 318i, the temp,fuel gauge +rev counter,not working?

SOURCE: Fuel Gauge always shows empty

see if there is any acces to the fuel tank cover under the rear seat, if it is then remove the screws and remove the sending unit sending unit inside the tank most likelly it will be bad, but if you don't feel like doing it, then take it to your mechanic but seems to be the sending unit inside the tank wich is the sensor trigering your gage is not good and need to be tested and replaced

SOURCE: electrical fault

It could be lamba sensor in exhaust gone faulty you need to get it on a diagnosic com puter really to check as modern engines have lots of sensor to monitor air fuel temparatures etc most garages have them now as all cars have electronic control units to control the running of the engine

SOURCE: fuel gauge has stopped working on my 318i 98

Fill it up, if it still doesnt work, try an auto electrician

SOURCE: Guages malfunctioning

This problem maybe solved a couple ways. The first, (and cheapest) is check all your fuses. BMW's sometimes have multiple fuse boxes. In the dashboard behind the clove compartment, under the driver's side or passenger's side dash( near your knees or sides of your calfs), and in the engine compartment under the hood. Fuses are relatively cheap if you do it yourself and are available at nearly all auto parts stores and many WAL*MART'S or TARGET'S.

If you've checked all the fuses with either a fuse checker (about $5 at an auto parts store) or by pulling out and checking each fuse visually (making sure to be very careful not to touch the contacts or not getting shocked by disconnecting the positive battery cable very carefully), another problem may be in your ECU (the car's computer or brains).

If the fuses are fine, I'd take it to a dealer to have them look at the ECU, it is one of those parts that you can't really diagnose yourself with out the right software and computer connections (very expencive tools, around $500-$3,000 each) but many local mechanic shops and all BMW dealers will have these tools.

First check the fuses. If you have trouble finding the fuse boxes, look in the owner's manuals.

I hope I could help you fix the problem.

SOURCE: speedometer not working but all other instruments

speedo drive sensor on transmission failing or loose or dirty connections