Tachometer always start to fail after 5min driving

[lizola]

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

[Davewjunior]

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).

[GeorgeK]

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

[vesnyder]

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!