What would cause a motor to rev up and down?

What would cause a motor to rev up and down?

If the engine can’t keep idling, it will keep trying to get the engine revved up to compensate. The cause of the erratic engine you’re experiencing could be a vacuum leak, sensor failure, or an EGR system malfunction.

Why does my RPM go up and down while in park?

If the engine can’t keep idling, it will continue trying to get it revved up to compensate. The cause of the erratic engine you’re experiencing could be a vacuum leak, sensor failure, or an EGR system malfunction.

What causes an engine to surge at idle?

A surge is usually caused by a fuel system management or drivetrain operation failure. When an engine’s computer can “hunt” or “surge” at cruising or idle speeds it is searching for program compliance, there is a problem elsewhere in the system. SPONSORED LINKS. Article published 2017-01-26.

What causes an engine to surging when accelerating?

Vacuum leaks can cause car surging when accelerating on engines with either a Mass Air Flow system (MAF) or Manifold Air Pressure (MAP) system. Regarding engine surging while cruising, it depends on the type of fuel injection system. An internal combustion engine needs a mixture of air and fuel to create a combustion.

Can a vacuum line cause an engine to surge?

Learn more Step 5 – If a vacuum line has caused a leak the engine will surge, as vacuum lines age they can become brittle and fall off the engine or accessory. Learn more Step 6 – If an air intake boot becomes torn and develops a leak it will cause the engine to surge.

Why does my car engine run rough while idling?

When your car engine runs as it should, everything should be smooth without any noise. When any number of things goes wrong, the engine can start running rough, especially while idling. By understanding the causes of a car engine that has a rough idle, you can resolve the issue easily.