Back to all

Idle Talk about Engines (Causes of Rough Engine Idling)

January 23, 2022

When you slow down at stoplight, your vehicle's idle should be smooth as silk.  But what happens when the engine is missing or idling roughly? That's your engine's way of telling you, "Hey, I've got something wrong with me and if you don't get someone to find out what it is, I may not start the next time you turn the key."

You can help your service facility if you can describe the problem in detail.  Here's a list of things to make a note of:

  • When is the problem happening, when the engine is cold or when it's been running for a while?
  • Does the rough idling occur when I'm accelerating or when I'm going at a steady speed?
  • Does it happen at high speeds?  Does it happen low speeds? Does it happen at both?

Make sure you describe the problem in as much detail because it will help a technician diagnose the problem.

One of the first things they'll check is how the spark plugs are firing.  Modern iridium plugs are supposed to last a long, long time.  But they CAN eventually wear out.  Inspecting the firing end can help the technician figure out the root of the problem.  Corroded or worn out spark plug wires, too, can contribute to an idling irregularity. 

There are other potential problem spots, too.  The technician may check the ignition coil, timing piston rings, valves and cylinder walls. 

If the mixture of air and fuel isn't correct, that may affect how smooth your vehicle is running.  Your service facility is equipped with diagnostic equipment that helps them pinpoint the problem.  Once that idle is smoothed out to the way it used to be, you'll be the smoothest operator on the road.

Tuffy Tire & Auto Service Aurora
3190 N. Aurora Rd.
Aurora, Illinois 60502
630-898-6688

More articles from Tuffy Aurora

The ?Man-Made? Engine Oil (Synthetic Oil Change)

March 8, 2026

If you own a newer vehicle, your vehicles manufacturer may require that it use synthetic oil instead of conventional oil. Synthetic oils are more stable, dont break down as easily, and provide better engine protection than conventional oil. All those things can prolong the life of your engine an... More

No Charge (Why Won?t My Battery Hold a Charge?)

March 1, 2026

When your vehicles battery is dead, it leaves you with that horrible, helpless feeling. A dead battery means it wont hold a charge, and there are several reasons it wont. One is age. Batteries have chemical and electrical systems in them that create power, and as time goes by, they wont work we... More

What?s That Yellow Squiggly Line Anyway? (What Warning Lights Mean)

February 22, 2026

You may have noticed when you start your vehicle, youll see several symbols light up on the dash. Theyre different colors and shapes, and sometimes its hard to figure out what each of those symbols mean. They are warning lights and symbolize something in your vehicle is sending you a message. I... More