Back to all

Idle Talk about Engines (Causes of Rough Engine Idling)

October 1, 2023

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 Plainfield
23846 W 135th St
Plainfield, Illinois 60544
815-436-1337

More articles from Tuffy Plainfield

TCB your PCV (PCV Valve Replacement)

March 15, 2026

Your gasoline engine goes through some exhausting work. Yes, it's truly exhausting, as in: it produces exhaust! And when your engine starts behaving like it's exhausted, such as running poorly or getting lousy fuel economy, the trouble may be something called a PCV valve. Did you know it's a ser... More

Don't Start with That (Bad Starter Motor)

March 8, 2026

We've all heard that expression, "That's a non starter." When it comes to your vehicle, that's not music to a driver's ears. That sickening sound when you start the ignition and instead of hearing the engine crank, you hear it slowly turn over and your dash lights go dim. There can be many reaso... More

Losing Your Cool (AC Condenser Replacement)

March 1, 2026

Its always more comfortable in your vehicle when you can control temperature and humidity in the cabin. Air conditioning, which is standard on most newer vehicles, is a vital part of that comfort, and a key component of that system is the condenser. The condenser converts the refrigerant gas into... More