What year is your Patrol? On the later 4.2's if the crank angle sensor is playing up it can also cause problems with the tacho. Cheers.Its not something thats worried me for the last six months but my tacho on my TD42 reads about 500rpm more than what its doing. Even with the motor off but ignition on its got 500rpm on the dial.
Any thoughts
Its a diesel.What year is your Patrol? On the later 4.2's if the crank angle sensor is playing up it can also cause problems with the tacho. Cheers.