Skip the auto shop - Our mechanics make house calls

Q: Car jerks and slows down

asked by on

When I'm on the highway going 70mph, the car would jerk when I press on the gas and the speed would drop down to about 50 or 40. When I press on the gas it either does nothing or the car jerks even more. If I just drive at that speed for a while it goes back up to 70. I usually drive to places closer than 30mins away and I don't have this problem. However, I need to drive 4 hrs to visit my parents a few times a year and that's when this happens. I have to drive home to vote on Tuesday and I'm wondering if the car can make it.

My car has 200000 miles.
My car's transmission is unknown to me.

Hey there. This may be a sign of a dirty or failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected into the motor. When this fails, this can cause an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This is what causes the hesitation or loss of power you describe. This may also cause a jerking type reaction by the car when pressing on the gas pedal as you describe. I would suggest having a professional from YourMechanic come to your home to diagnose the jerking issue and move forward with repairs.

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: White and blue smoke coming out of exhaust

Hi. The first thing that comes to mind is the turbo seals. When they leak, pressurized oil enters the intake of the engine. Check your oil level often. Repairing or replacing turbo’s can be very expensive. The other possibility is...

Q: Car overheats occasionally and will not start

Based on the information you gave about your 2003 Honda Civic, it sounds like you have a cooling system issue. It could be your cooling fans, radiator cap, water pump, thermostat, or even a plugged radiator. Since this is an...

Q: For someone who can do all the work themselves, is a Cadillac expensive to maintain? I.e. parts wise, frequency​ of needed work.

Hi there. The service and maintenance jobs that are required on Cadillac's are not as simple or generally automotive in nature as they once were. In fact, most simple jobs like replacing spark plugs require advanced diagnostic equipment to reset...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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.