1995 Nissan Maxima 6 cyl Front Wheel Drive Automatic 126000 miles
My tachometer sometimes bounces everywhere and in the most case about 75 percent of the time when it bounces up and down is when I gas it to stay in the flow of traffic. But just would like to know why it bounces everywhere on these occasions when I do this.
The tach follows the engine speed. At lower gears, the tach will go up until the transmission shifts up, then the tach will go down (as the engine speed slows down) until you hit the cruising speed. In your case, cruising at 70 mph, your tach should stay at about 2500 rpm.
When you are keeping up with traffic, you have to step on the gas, thus the transmission shifts down (lower gear higher rpm = higher tach reading) until you reach your desired speed, then the transmission shifts up (lower engine speed, lower tach reading).
Next time you drive, turn the radio off, you will notice my explanation.
February, 17, 2010 AT 9:43 PM
My 1997 Maxima runs very well, having almost 365k.
Lately the tachometer has been sticky getting into first gear, and then it seems to run higher at highway speeds. At 55-60 mph it will be about 3000rpm. At 60-65 it will approach 3500. It will jump back down going down hill. I am in the northeast, but in flat roads and warmer temps (when driven down south), it seems to behave more normally with intermittent spikes.
I would normally get 400-449 miles on a tank, but if I need to stay at highway speeds, I can only get about 300-340 miles.
Could this be temp/load relalted? The temp guage is normal and the heater is fine. I had oil, gas and fuel filters changed, and a transmission flush.