Skip the auto shop - Our mechanics make house calls

Q: When I start my car it the idle is very jumpy and the car feels like it wants to die

asked by on

When I start my car it jumps from 2000 RPMs all the way down to bear lyrics none then almost dies jumps back up to like a thousand then back down and it just keeps doing that

There are several possible causes for the idle to fluctuate like this. The most common causes are a faulty/dirty mass airflow sensor, a vacuum leak, an oxygen sensor that is reading incorrectly, or an idle air control motor that is unable to react quickly enough.

The most effective way to diagnose this situation is with a diagnostic scanner that can relay the data stream from the mentioned components in real time and compare that data to the acceptable parameters set by the manufacturer for each component.

Alternatively, you can perform physical inspections on most of the components, it just takes more time and knowledge. You can take a look at the vacuum hoses to see if there are any that have come unplugged or if the hoses have dry rotted and cracked. You will normally hear a "whistling" type sound from a vacuum leak.

You can also remove the idle speed control motor to see if there is a build up of carbon, which will keep it from being able to control the idle speed quickly enough to maintain a steady idle. There are several other possible causes for the idle to fluctuate, and if you need some help identifying the problem, feel free to contact YourMechanic to help you diagnose the rough idle and proceed with repair.

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!
  • Home
  • Questions
  • When I start my car it the idle is very jumpy and the car feels like it wants to die

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: I'm wondering why my car won't start in 50 degrees or lower temperatures

Hi there. If your engine is cranking over and it's difficult to start, the issue may be caused by a damaged distributor or ignition coil. Especially if it's cracked and condensation is seeping into the electrical system. Other possible...

Q: Hello I have a lancer and it just shut off on me driving on the freeway..sounds like its just winding like if there's no belt on i

A possibility is a broken timing belt but there are other common possibilities such as an engine sensor failure, ignition switch failure, fuel pump failure and so forth. The good news is you do not have an intermittent problem but...

Q: Transmission wont go into gear

Check to see if the transmission will engage in Low, 1, or 2. You can shift manually to those positions. If it does engage, that could signify a broken apply band (such would require rebuilding the transmission). If the transmission...

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
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.