speedometer not working
 

i have a bmw 84' 318i and the speedometer only works some of the time it will pop back up and down what could be the problem
any information would be greatly appreciated.

Is it automatic or manual. If you want go to this site http://www.realoem.com/bmw/and you can see were your speedometer drive gears and everything are located. In an automatic it is located in the transmission, on the driverside I believe. There is also one on the rear axel housing at the back of the housing. If the gear in the transmision is worn and just catches, that would cause your problem, or a malfunction with the one in the axel would also cause that.

its a manual transmission

I would check the sensor on the rear axle and the wires leading from it.

hey thanks allot ill try it.

Right - it's either the sensor or the gauge, and 9 times out of 10, it's the wire hanging slightly loose at the back of the transmission...

-Wayne