Back to all

Idle Talk about Engines (Causes of Rough Engine Idling)

November 14, 2021

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.

Commerce Auto Repair
9575 Commerce Rd.
Commerce, Michigan 48382
248.363.3749

Need Service?

Request a Quote

More articles from Commerce Auto Repair

Stop Right There!

October 25, 2026

Your vehicles brakes are only as good as its master cylinder. This part is truly is the heart of your braking system, because if it isnt working the way it should, the rest of the brake system cant either. The master cylinder is what takes the pressure you put on the brake pedal and ultimately... More

A Smart Inspection, Peace of Mind Before You Buy

October 23, 2026

With the price of new vehicles these days, you might be thinking about saving some money by buying a used one. But when you go to look at a vehicle, how in the world do you know what youre getting into? A look around the outside and a short test drive likely doesnt give you the confidence that... More

Save Your Tires and Fuel: Why TPMS Is More Than a Warning Lightc

October 11, 2026

You know that little light on your dashboard that looks like a tire? Dont ignore it. Its a lot more than a warning light. Its trying to tell you something that can protect your tires, improve your fuel economy and keep your vehicle traveling safely down the road. Its called TPMS. The abbreviati... More