Cold Idle + SLIGHT Rev = Major Dip in RPM (Almost sounds like about to stall)

[kanniballl]

Hi,

I know there are posts about rough idles during cold starts. However, this has a slightly different twist than the other mentions, so I don't know if this is something different (or worse).

I put "plus" gas in my car from a station we trust. During cold starts, my CTS idles rough (rougher than my 91 Olds, but that's not the problem I'm concerned with). Warm idles do well enough (though not perfect).

When cold-idling, it sits around 1k RPM. However, if I quickly just touch the gas to rev it slightly (like 1.2k) and let go, the RPMs dip between 500 and 750 RPM. However, when it does, it sounds like the engine is about to stall. The engine sound cuts out entirely on its way down, and then you hear it again as it goes up.


Anyway, this has me concerned. I'm going to try to see my dealer over the weekend to see what I can do. Unfortunately, it's far enough that my car will be completely warmed up by the time I get there and it will be warm enough outside to prevent it from going to a cold start very easily.

Should I be concerned?
980 miles (yes, still less than 1k)
2006 CTS
3.6L V6
Luxury + Sports packages
Sunroof
GPS + 6CD Changer

[Caddy Man]

my car does this too in cold conditions only the first 10-15 seconds at start up. I dont think its that big of a deal to take it to the dealer. at least not for me.