Cold Stalling, Torque Converter?
My 07' 2LT Coupe has been stalling when the car is cold (only from Oct. to Mar.) for the past 2 winters. During the summer, it is perfectly fine (stalling wise). It has been shifting funny in my opinion for 2 years, year round. On a straight away at a constant speed, it feels like its pulling me forward in between shifts. The car has never been above 19 mpg since I got it, and it has now read 15.2 mpg for the past 3 months.
I have had this car at the dealer more than 7 times for a week each time, but they claim the car has not acted up for them at all and never throws any codes. Every single time I get into the car, the first few times I come to a stop, the car shudders and stalls out. Finally, after two years, I asked my neighbor who is a mechanic to come over and back my car out of my driveway (uphill) to show him what its doing. The car acted up like crazy (shuddering and stalling in gear) and he said he is 100% sure it is a transmission issue, most likely my torque converter. He was able to replicate the problem over 10 times in a row so I'm hoping he knows what he's talking about.
Anyone here have any input? Does it sound like the torque converter is the issue? If so, can a torque converter be changed without removing the entire engine? I'm more of an electrical guy than an engine guy so any help/input is greatly appreciated.