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.

A: Hey there. This may be a sign of a dirty or...

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・Save up to 30%

Get a quote

What others are asking

Q: Engine roar while braking/ stuttering while accelerating

Hi there. If the engine noise is happening only when the car is in forward gear, the issue might be caused by a damaged CV joint or the wheel bearings. However, if you're experiencing this sound while braking, it could...

Q: Blinking lights come on upon startup

This signifies that there is a malfunction with the security system. A scan tool will be needed to determine what fault codes are stored. Once the codes are retrieved this will give the mechanic a diagnostic path to follow to...

Q: Engine making chirping sound

Belts chirping or squeaking in annoying but usually not too serious. I've seen brand new belts chirp because of the ink that's on the belt for the part number and barcode. However, it could also be a bearing in a...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...