Hesitation at idle?

[Nuhgets]

I tried searching the forum for this, but I'm horribad at narrowing searches in general, so I do apologize for a repeat if this is.

A quick answer is all that's required really, but when I sit at idle (after cold start finishes settling) I sometimes feel the car shudder a bit and watch the RPMs drop under the 500 mark. No load on the engine at all, just simple neutral idle without the clutch pressed. It has not stalled from this yet, however.

This happens just about all year round (as far as I could tell). I do most driving on local roads and highways. I'm in Illinois in the Western suburbs.

Is this normal?

 

[SuperSonicRS]

Happened to me, checked and regapped the plugs and it hasn't happened since

 

[Nuhgets]

I figured it could be a plug issue, but I didn't want to assume. Thanks for the response! I think I'll check out some new plugs for my Sonic this weekend. I've had promising results with E3 plugs in my last car, but I'm not sure if they make them for the Sonic yet. It seems a lot of Sonic enthusiasts are running NGKs... Would Iridium plugs be acceptable?

 

[SuperSonicRS]

Ngk iridiums should be what's in there already, just pull the plugs and make sure they are at 0.028".

 

[SuperSonicRS]

I usually run iridiums for 60k plus miles. There is no need to replace early unless you see noticeable wear or damage or having a problem such as misfire, smoking etc.

Also stay far away from multi prong plugs such as Bosch +2 or +4. I've ran E3's in the wife's Taurus with no problems, but no noticeable gains either. E3's differ from the Boschs because the prongs are "bridged" together.

 

[Nuhgets]

Thanks, SuperSonicRS! I'll check out the gap this weekend when I take my car into the shop.