Skip the auto shop - Our mechanics make house calls

Q: My car periodically starts with a high idle.

asked by on

My car will start with a high idle, about 2000+ RPMS and then subsequently lose power while driving. The car will sputter and not go above 50 miles per hour. This happens sporadically and I cannot determine what causes this or how to fix it.

My car has 95000 miles.
My car has an automatic transmission.

A: This is a common sign of a failing mass air...

This is a common sign of a 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 often times results in the engine starving for air or fuel. This is what causes the hesitation or loss of power you describe. This can also cause the engine to struggle to idle for the same reason. This may also be related to a vacuum leak which will cause the car to idle high as you describe due to a lean fuel condition. At higher RPMs, a lean fuel condition will also cause a loss of power. I would suggest having a professional from YourMechanic come to your home to diagnose and replace this sensor.

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: The truck starts then stalls or shuts off

This could be a wide variety of potential issues ranging from a vacuum leak, bad idle air control valve, low fuel pressure, bad coil packs, or many other possibilities. When this happens you should have a Check Engine Light on...

Q: Tire pressure Monitor ?

This is a common issue with many high performance tires and can be caused by something as simple as the obvious, a faulty tire pressure sensor. I would recommend starting with checking all of these to be sure they are...

Q: When car is off and in park I can turn the wheel left and right and makes a clicking/clicking noise.i have changed both ball j LRT

The noise will be most easily pinpointed if you have an assistant turn the wheel while you, or a mechanic, hone in on the location. There are quite a few other potential sources of the noise such as the upper...

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 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...
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...