My 2005 Honda CR-V (240000 miles) has needed minimal maintenance (overall). A real work horse! However. I am tired of living with a rough idle (and all lights flickering). The battery and alternator were replaced last year, and recently I had a tune-up. What more should be checked or “timing” checked to smooth a rough idle? (I assume the flickering lights go along with the rough idle?) I thought for sure the tune-up would do it. Is there a voltage regulator on today’s cars?
What comes to mind when you read these symptoms? Or, is it just old age?
“Tune-up” is a nearly meaningless term, nowadays, generally used to mean spark plug replacement. This usually doesn’t make the engine run better.
Battery and alternator (which includes the voltage regulator, unless it’s in the main computer) are very seldom factors in poor idling.
It could have an engine vacuum leak (from any of various places), carbon build-up in the throttle body, a faulty or dirty mass airflow sensor, or a faulty idle speed controller, and that may not be an exhaustive list.
Have your nearest AutoZone, O’Reillys, PepBoys, etc do a free charging system check and read the diagnostic codes. The mention of lights flickering concerns me; a rough idle shouldn’t cause that.
For the rough idle, I second Gary’s options. It also helps to find a message board specializing in your vehicle; they’ll direct you to the common causes on that type of vehicle and often will have guides ( with pictures ) for common repairs like this.
Checking the tachometer is a good thought, but the needle does not fluctuate. Isn’t that odd?
Also, you mentioned motor mounts. Are you thinking the whole engine is swaying on fatigued motor mounts?
Motor mounts cannot cause rough or low idle – these are aspects of how the engine is running, not how it is held in place. They can cause vibration at idle.