Back to all

Idle Talk about Engines (Causes of Rough Engine Idling)

April 5, 2020

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 Lake In The Hills
59 West Acorn Lane
Lake In The Hills, Illinois 60156
847-854-9850

More articles from Tuffy Lake in the Hills

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

June 9, 2025

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

Steering You Right (Tie Rod End Replacement)

June 2, 2025

For drivers, S stands for safety. And there are three other words that start with S that are all equally important: starting, stopping and steering. For your vehicle to be at its safest, all three functions must be in top shape. Steering is one of those things we take for granted. After all, y... More

Smooth Operator (Shocks and Struts)

May 25, 2025

Few of us ever drive somewhere without encountering some pretty rough roads, and it's amazing how well our vehicles are able to smooth out the ride. Thank your shocks and struts. The two parts are similar. Some cars have shocks in the rear, and struts in the front. Others have struts all around... More