Couldn’t find my old post…09 civic LX sedan 1850 miles. Hear a ticking in concert with rpms sometimes.
Here’s what I found from another place. Hope this helps someone else…
" As for me, I’m an Acura Master Certified Tech with 10 years experience on Honda/Acura.
I just noticed the ticking noise on the Civic yesterday, after getting out while it was running. So I decided to get to the bottom of it.
I pulled it into the shop when it was stone cold, popped the hood open, and let it idle while I stood waiting with the mechanics stethoscope. After 5 min the noise started. AH-HA! Just as I thought it might be, it’s the purge control solenoid valve above the intake manifold happily ticking away. Unfortunately purge control valves are notoriously noisy, and this would be considered NORMAL.
Some of the Acura vehicles have a similar setup, with an equally noisy valve. More underhood insulation on Acura vehicles makes it harder to hear than on the Civic which has almost NO insulation.
For those not in the know, the purge control solenoid valve controls the flow of gasoline vapors from the gas tank so they can be burned in the engine. The valve doesn’t start cycling until after the car is almost fully warmed up, which is why it isn’t noticeable when cold.
Just for grins, I scoped the injectors (loud, but not nearly as noticeable as the purge solenoid) and the valves (smooth like a well oiled sewing machine) therefore I have to lay the blame squarely on the purge solenoid.
I’ve been using Mobil 1 and Pennzoil Platinum 5W-20 with Honda filters, car has 15k and still runs as smoothly as the day it was new.
Hope this helps some Civic owners sleep better at night, I know some people here love their Civics like kids love the ice cream man in July! "
Hope I’m not violating any rules by posting this here but wanted to forward this info to late model civic/acura owners here. thanks.