11-24-08, 12:33 AM
OK so lately my 02 SLS has been acting weird when it's really cold out. Like today it was 29 F and when i start my car it starts up fine but i notice that the AIR pump does not come on at all and the car will actually sit and idle around 1000 rpms always, instead of 1200-1300 like it normally would and then idle down to like 750-800 rpms.
Is that normal?
Also when it's cold like this the transmission shifts into reverse or drive really hard. Like slamming into gear sometimes....only on the first start up.
11-24-08, 09:49 AM
A.I.R. supplies extra oxygen in the exhaust which is used to light off the cat quickly under different conditions, so maybe the before and after cat O2 sensors are saying "well, we don't need extra oxygen right now". Probably nothing to worry about. (If the fuel/air ratios going to/from the engine are very close to perfect for the current operating conditions, A.I.R. is not needed). The 1,000 rpm fast idle for the first 30 -40 seconds is probably OK also. As long as it drops down to the 700 - 800 then later down to 650. Where are you engaging D the first time? At 1,000 rpm? If so, with cold fluid you'll get an aggressive first/R engagement. Wait 'till it drops to the 700 - 800 point.
11-24-08, 10:20 AM
My car has the same rough engagement on cold mornings. I asked my boss at the Cadillac dealership and he said it's perfectly normal and there isn't anything to worry about.
I think what you are seeing is normal. I've recently noticed below 30 deg. starts that my idle is at about 1000 rather than the usual 1300 as well.
As for the hard shift into reverse, I experienced that the other day for the first time. Just kind of shrugged it off.