2009 Commander Black Exhaust Smoke
Hey guys, I'm writing back with regard to the Jeep I bought recently.
This was a 1-owner "certified pre-owned" vehicle with 85,000 miles which the dealership has been unable to resolve issues they promised to fix; transmission shudder and drivability issues.
My previous post was about the transmission which after the dealership stopped returning my calls I started checking into myself, and found it was 3 1/2 quarts low on fluid. After resolving that I still have an occasional torque converter shudder on slight grades when going from lock to unlock, etc, but otherwise it seems much better. Not sure how that is going to end up yet, time will tell.
The other big issue it has is after driving on the highway for more than 15-20 minutes, and then exiting the highway and going through normal stop then go, the engine stumbles hard then blows out a HUGE cloud of black/gray smoke which takes up to 30 seconds or so to clear out then it runs fine again.
Overall, I've got the engine running pretty smoothly most of the time, but this highway thing is really weird.
The other thing it does, is while driving on the highway, if I have to slow down, then speed back up from say 60-70mph, it will not accelerate AT ALL when the throttle is opened, even at wide open; what it will do, is after wide open, then backing out of it, as I back out of the throttle, it will begin to accelerate almost as if in reverse to the throttle position. In other words, at WOT, there is nothing, but the more I slowly back out of it, it then gradually begins to accelerate back up to 70mph.
Overall, gas mileage is good now, it started at 9-12mpg when I first bought it.
It will get 18mpg at 80mph now (with winter tires on), and around 15mpg combined city/highway, which is about the same or maybe a little better than my previous 4.7L Commander.
I drove 500 miles yesterday and this highway black smoke thing is 100% repeatable.
Any ideas what's going on here?
I really appreciate your thoughts and input!