My 2011 Civic LX (8th gen) has a 660-670rpm idle in Park, with no loads, warmed till radiator fan comes on. Have been searching the net for an hour and can’t find any definitive reference for normal warmed-up idle speed for this R18A engine. Can anyone direct me to good source? BTW, just did Honda throttle-position-relearn procedure, and it didn’t change the idle. I suspect that idle may be a bit low, but am in process of ruling out possibilities to explain a tad excessive vibration, like loose engine mounts. Would like to just confirm if this is normal idle speed.
Around 600-700 RPMs at idle in Park sounds about right to me. What makes you think there’s a problem?
On a 2011, you may be just experienced Older Car Syndrome, where stuff doesn’t run like when it was new.
The best source is likely sitting right next to your head when you are working under the hood of your Honda. Unless your Civic was in a collision, there should be an emissions-related label on the underside of the hood. It might look slightly different from this GM label, but it should be reasonably similar:
This one might look more similar to the label that is glued to the underside of your hood.
That emission sticker is for a 1986 model year vehicle.
Back when you COULD adjust the idle speed.
Is the idle speed on the OP’s 2011 Civic manually adjustable?
If not, then your suggestion of cleaning the throttle body is likely the only solution.
This is for a 2005 model year Honda.
For the 1.8 L w/EPS I’m seeing 670 +/- 50 rpm , warm engine, trans in neutral, no unnecessarily electrical loads. Will probably increase a little if you turn the headlights on bright.