You're driving your car and checking your speed. You notice to your left the tachometer needle not moving, or moving erratically. The tachometer counts pulses generated by the ignition system and alternator, and it displays the speed of your engine in revolutions per minute (rpm). Various factors may cause stickiness in your tachometer.
See if your tachometer tends to stick more when it is cold outside and your engine has not warmed up yet. Look to see if the problem subsides once the engine runs for a while. If temperature variations causes stickiness in your tachometer, warm up your engine before driving.
Inspect your tachometer for noticeable dirt and dust around the base of the needles. If the area appears dirty, use a canned air cleaner to spray around the inside of the tachometer to clean out particles that may be causing the stickiness.
Loosen the nuts holding the back clamp to the tachometer needle. If the problem persists, replace the tachometer.
Check to see if there is any moisture inside the tachometer housing. Fogginess on the cover or stains inside will indicate this. If moisture shows, replace the tachometer. The base holding the needle has probably rusted.
