Rough cold starts with a 2.4L Twin Cam
I have an Alero with a 2.4L Twin Cam engine. It'* a 2001 model that was driven hard by my sister for four years since 2006, and it now has 180K miles having started with around 120K when we bought it.
From the factory, it has a speed density tune, and there used to be two air boxes with one of them simply sitting on the throttle body. That one broke at the ring where it sat, and so I replaced it with a tube that goes to the now single air box. This may singlehandedly explain the cold starts as they're not so bad now that I suppose the engine has gotten used to the new setup under the newly cold weather.
However, I'd like to make sure. What are some decent ways to check? I'd like to do a compression test and have a tester ready to go, but first I'd like to sit back and think about it. When I started it in its first cold weather since the new air intake was installed, it started rough and idled for about 2 seconds as if it had monster cams; then I noticed a cloud of smoke that erupted out of the exhaust, but all things went back to normal after that.
So, all in all, with rough driving and poor maintenance for 60K of its latest miles, this Alero could have bad rings, valve seals, etc. First, I'm going to slap some Seafoam into it and enjoy the amazing smoke show. I'll run cans of Seafoam until there'* either minimal or no white smoke out of the back. Then I'll do a compression test. What else should I do? Any general guesses about the rough starts in cold weather?
94 STEi and 99 SLO