Q: My vehicle stumbles and hesitates, and the RPM go crazy

asked by on

When i first turn on the car the engine does a sort of 1-time kick not a smooth start. Also when i turn the ac on the rpm goes up about 500 and comes down, you can hear the engine rev hard. As i speed up all the way to 30 and let go of the gas to maintain that speed, the whole car does like a double shake as if it was about to go faster but does a harsh kick. And when im maintaining a constant speed of about 42 or 43 the rpm doesnt stay still, it moves up and down in 500 intervals and you can feel the engine reving without me even pressing the gas! I already changed the cam shaft position sensors and changed transmission oil even added some lucas product so the transmission wont slip!

My car has 158467 miles.
My car has an automatic transmission.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My vehicle stumbles and hesitates, and the RPM go crazy

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My car is jerking and hesitating when accelerating

This may be a sign of a dirty or failing mass air flow sensor. The mass air flow sensor reads the air intake as it is mixed with fuel prior to being injected into the motor. When this fails, this...

Q: When stopped at traffic light. My car hesitates and pops in the engine compartment unless you hold down the gas pedal.

Hello there, many faults will cause a popping noise in the engine compartment of your 1998 GMC jimmy. You have done well replacing the spark plugs, wires, cap, and rotor. If the problem is still there after all those repairs...

Q: Starting problem, engine revs at low RPM in drive - 1999 Chevrolet C3500

It sounds like the Idle Air Control valve is gunked up. It may be possible to clean it, or it might have to be replaced. A YourMechanic professional can help to diagnose the stalling issue and replace the idle air...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.