Your tachometer needle is dancing up and down possibly because you have a problem with your fuel injectors. If they are leaking fuel into the combustion chamber, this will cause your engine’s RPMs to rev higher than normal. The more common reason why your tachometer needle is dancing up and down, however, is that your engine has a vacuum leak. Engine vacuum is transferred through hoses to power accessories and components. ER Auto Care lists the other signs of a vacuum leak below. These signs usually accompany a sporadic tachometer needle caused by higher engine revolutions.
Accessory Malfunction
One of the clear signs that your engine has a vacuum leak is if your vehicle’s accessories are malfunctioning. The accessories that are powered by the engine vacuum may not be getting the power they need to operate if the vacuum pressure is leaking out of the hoses.
Check Engine Warning
Another sign of a vacuum leak is a check engine warning on your dashboard. The engine control module will pick up that there is too much air in the engine, which is being caused by the vacuum leak, and it will turn on the check engine light to let you know there’s a problem. Leaking vacuum hoses release excess air into the engine and this causes the performance issues were going to discuss next.
Lagging Acceleration
First, you may notice that your acceleration is lagging. Even though you press down on the gas pedal, your vehicle may hesitate to respond. It may sputter and even threaten to stall before it finally picks up speed. This is a sign that there is too much air in the combustion chamber and this is affecting your vehicle’s ability to respond when you press down the accelerator.
Lagging Engine
This problem also occurs in your engine as you pick up speed. Your engine may stutter and sputter as you pick up speed and then continue to hiccup when you are driving at your desired speed. Again, when there is a lean fuel mixture in the combustion chamber, your vehicle is basically fuel-starved. This causes the engine to struggle to keep up speed.
Suction Noises
Finally, you may be able to hear the vacuum leak if you can hear suction noises coming from the engine. Minor vacuum leaks also make hissing sounds.
ER Auto Care is the best auto shop in Plain City, OH. We also work tirelessly to be the best auto shop in Columbus, OH, so you can call whichever shop is closest to you to schedule an appointment for an engine inspection. We can repair your engine vacuum leak.