[Gremlin]

I posted this back a few months ago. I have a 2LT I been having transmission down shifting for no reason at all. On flat roads traveling at 70 mph the car will shift to 4th from 6th. I have to goto manual mode and shift it back to 6. Then there are time it when I notice the tack jumping around from 3 to 4,000 rpm's. The car shifting from 4 to 5 and back for no reason. Still no check engine light yet, I had to have the Vacuum manifold replaced because of traction control issues. Would like to know what going on now. In manual mode when the car is coming to a stop light and it changes just as you get there the car shifts to 1 before the car is stopped and it clunks when shifting to 2.

And now, I live in Minnesota, the temp is colder for the last few weeks. The car works fine no weird transmission shifting, car run smoother that ever. In October the we had a few day near 80 and the was acting up shifting weird. Can it be a heat related issue? It get warm it acts up cool to cold and it run fine.

 

[Silver LTZ]

I think I replyed to your other post, but I too agree it is weather related. When the Malibu was my daily driver my before I got the Speed3 I noticed the same thing. I live in north FL, so it is hot more then cold. But we had the coldest winter in 20 years last year and the car drove smooth as glass. Then come spring, it started to do it again. I have given up on the dealerships, they can't fix crap related to this. Thankfully it isn't that bad, and doesn't really bother her on her 2 mile daily commute since it is her car now. But it will be payed off next year, and I think we will trade it in.