New guy with question about idle rpm

[J.T.]

Hey folks, new to the forum. Have had the 2006 Vibe going on 3 years now, never any issues. Today, at 111K miles I changed plugs to NGK Iridium IX (it had the NGK Iridium IFR5A plugs) properly gapped and torqued, changed oil & filter, and air filter. Now, the idle has dropped about 400 rpm from where it used to be. When in gear (auto trans) at a stop, the car shudders and the tach shows about 450-500 rpm. when I push the gas pedal a bit, it smoothes right out with a few more rpm. No loose hoses, wires, etc, ScanGauge doesn't show any codes.Any ideas what could have caused the idle to drop?JT

[jkm311]

From one 2006 owner to another, welcome. Did you disconnect the battery to put in the new plugs? After doing so, the system will need to "relearn" your engine's performance. You should see it return to normal after a couple days. Maybe even sooner...I know mine dropped into the 500 RPM range when I cleaned my MAF sensor last summer. Took a couple turn overs and 30-40 miles of driving to get back to normal.

[J.T.]

Thanks for the quick reply. I did disconnect the battery, but I thought the adaptive mode in the ECU pertained only to driving style, that idle (warm and cold) were set values. Looks like "search" wasn't my friend today, hundreds of posts, and I probably didn't read the right ones.I'll know by tomorrow, will post results then.JT

[markdb]

My 04 shudders a bit while in drive (stopped) or reverse.There is a fine line with the rpms whether or not it vibrates or is smooth.I made the mistake of trying to compensate for this by adjusting the idle control screw under the hood. It definitely smoothed out the idle, went from about 800 to 1000. But the computer did not like this, spit out a code, so I changed back.Some say that it could be worn or cracked motor mounts that cause the vibration. Seems to be a common problem with vibes.

[J.T.]

Put a little over 100 miles on the Vibe today, and somewhere along the trip it fixed itself (ECU reset), and all is well again.Thanks for the heads up on the battery disconnect/ECU reset.JT

[06pvibe]

<COOL!>

[jkm311]

Glad it worked out! I'm sure this conversation will ring in my head when it comes time to replace my plugs.