Tachometer always start to fail after 5min driving
 

Hi Can anyone help? Thanks.
I'm a newbie here.
The Tachometer of my 3.2 always works fine on starting and consistently dies on me after 5-10mins driving.
This makes me think its a mechanical problem that is exacerbated after warming up

Is the "tachogenerator" a mechanical part? --> Its the source of the signal to the DME right? If so, where is it located. Thanks

I've had the same problem for awhile now so I'll be watching this thread. Mine will stop after a few minutes of driving. Sometimes tapping on the gauge will help or driving over a bump will make it work/stop working. New ignition coil (happened with the old one too).

I'd say a corroded earth that gets worse as the wiring heats up.

My tach went crazy when my alternator went bad. I was on a long trip and when I got close to home it freeaked out! I suspect it is something electrical. Start with checking teh charging system - alternatory and voltage regulator. Good luck!