Protection Posted June 10, 2013 Report Share Posted June 10, 2013 06 Grand Prix GXP 5.3L Smokes when throttling out of AFM (4 Cylinder mode) For example; Cruising at about 65 MPH for an extended amount of time in 4 Cylinder mode.. Accelerate to merge or pass and I have a nasty puff of greyish smoke out the back. Does anyone elses do this? my car has 140K on the odo and runs/drives perfect. Nor does it smoke that bad WOT.. it does a little bit but not nearly as bad as it coming out of AFM mode. I almost want to get the AFM disabled somehow.. NOT to mention it sounds like a damn Subaru with my new exhaust setup in AFM mode. My question is.. Is the smoke normal with my mileage? Does anyone elses LS4 car do this? I seen oil consumption is a little common in these LS4 cars but that Cloud of smoke cant be good. Quote Link to comment Share on other sites More sharing options...
Cordell Posted June 10, 2013 Report Share Posted June 10, 2013 Oil consumption is very common, and the AFM is very hard on the engine causing these issues. Sounds like the rings are going south letting oil into those cylinders while the AFM is active. Have replaced a couple engines in the past for that issue. If you like the car and have it fixed, blocking off the AFM passages and changing the lifters, then having it tuned would be something I'd do. You can read up on these issues all over the internet as they are fairly common especially with mileage. Quote Link to comment Share on other sites More sharing options...
Protection Posted June 10, 2013 Author Report Share Posted June 10, 2013 So essentially im due for a rebuild. Couldn't I just switch to some ls1 stuff in the top end? like cam and vavletrain? Quote Link to comment Share on other sites More sharing options...
TTQ B4U Posted June 10, 2013 Report Share Posted June 10, 2013 Oil consumption is very common, and the AFM is very hard on the engine causing these issues. I completely forgot about the oil eating of the LS4. Mine when through it even when new. OP.....Again.....good luck. Quote Link to comment Share on other sites More sharing options...
Protection Posted June 10, 2013 Author Report Share Posted June 10, 2013 I think it'll be fine. I really don't see engine failure or anything like that anytime soon but I would like to look into non AFM HEADS/CAM setup and just do away with it. Quote Link to comment Share on other sites More sharing options...
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