Skip the auto shop - Our mechanics make house calls

Q: On highway, car jerks and RPMs rise sharply

asked by on

When on the highway (and this only happens on the highway), my car starts jerking as if it wants to go faster. On its own, it will jump from 2,000 rpm to 4,000 rpm and this goes back and forth. I have to floor the accelerator before it will properly run. What is causing this?

A: When an engines rotation speed increases th...

When an engines rotation speed increases the speed should increase. If it isn’t, then there is likely an issue with the torque converter (an automatic transmissions clutch). If the speed is increasing, it could be an issue with the cruise control. Is it possible the cruise control was turned on by accident? It is also possible the vehicle has a vacuum leak as that would cause RPM fluctuations as well. A certified professional from YourMechanic can inspect the jerking issue and pinpoint the appropriate repairs to have this corrected.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Mazda 6 reliability

While we are not permitted to endorse certain makes and models of vehicles, we can tell you there are several other websites that not only have customer reviews, but also list the common problems. Often you can find great information...

Q: Exhaust system

The sound of the exhaust is not determined by whether it is a turbo-back, or a cat-back system. The determining factors for the amount of sound that comes from a given system are the size of the piping being installed,...

Q: When accelerate, car hesitates and jerks

It's hard to say the shop is wrong when they have been able to visually inspect the car while I have not. If you do not trust the shop's diagnosis, it cannot hurt to get another mechanic to take a...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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.