- Apr 13, 2013
For some time on my 02 Accord, I've noticed this intermittent issue when fully warmed up. When idling at a stop light, the RPM's drop below the tick mark below 1000, which I believe is 500. The engine then makes a slight chugging noise and idles not so smooth. It's more pronounced when the car is in park. Turning on an accessory like the headlights or A/C quickly brings RPMs back up to 750-ish again and all's normal. Car never stalls, accelerates fine when under load and otherwise runs great. No CEL is present and no overheating. Cold starts are normal at 1250-1500 RPMs. The idle doesn't bounce around like Honda's typically do when the IACV is messed up so I'm not sure if that's the issue. Things done so far: -Cleaned throttle body -Fresh oil change -ATF drain & fill -New OEM front engine mount (old one was cracked) -No apparent vacuum leaks -New air filter -New NGK spark plug wires -New OEM cap & rotor -NGK Platinum spark plugs ~2 yrs old. Properly gapped and tightened. -Bottle of Techron fuel system cleaner My coolant is about 7 yrs old. The level's good and there are no leaks but I'm wondering if there's air in the system after all these years. Eric the Car Guy says coolant's the first place to check for Honda idle issues. I'm going to bleed the system out and see what happens. What do you guys think?