So, first a little recent history with the vehicle: I just bought my 2016 Volt w/ 46k mi around the beginning of November, and a few weeks ago the CEL lit up. I scanned for trouble codes with EngineLink + an LELink adaptor, and found P0401 (EGR flow insufficient). I spoke with CarMax, where I bought it, and they had me bring it in to check it out. They confirmed that it needed a new EGR valve, and EGR cooler. They didn't say anything about the car being unsafe to drive, and since I'd been using it for a few weeks at this point, I figured nothing of it. I drove home that day, on gas, without issue, but while cruising on the highway at ~80mph the next day, as soon as the engine got up to temp there was a TRAIL of smoke coming from the car, and when I pulled over, the whole cabin filled with smoke and me and my wife had to get out of the car. I let it cool down, and was able to make it back home, which was yesterday, and was able to get it to the dealer today where I've dropped it off until the part comes in (it's under 60k mi, so they're having Chevy do the repair under powertrain warranty).
Additional info that might help: the smoke was white/light-colored, and smelled strongly of burning plastic or rubber; my wife thought it was a tire based on the smell. During the whole ordeal(s), the car never actually seemed to RUN any differently/worse. From voltstats, the previous owner drove it nearly 100% on gasoline (go figure...), and their overall average was 40mpg. Since buying it on 10/28/18, it's now nearly at 59k mi, about 45-50% of those miles are EV, 100% have been HIGHLY enjoyable.
However, I'm worried about a few things: first, what do you think could be causing the car to run OK on gas if I'm cruising lightly between 25-65mph, but any faster and it works to hard and overheats (coolant temp in DIC jumps past 212F when problem starts), any slower and there's not enough airflow to cool it and it overheats (same jump in coolant temp seen)? I can easily replicate the stationary issue by running the car in Mountain Mode with the battery dead, to force the engine to "idle" while stationary. Second, do you think any long-lasting/other damage may have been done? I've emailed the service guys over there, who so far have been fantastic about fixing a few other little issues (missing wheel well liner, etc), but I haven't heard back since they're not open on the weekends. Any input is greatly appreciated!
Additional info that might help: the smoke was white/light-colored, and smelled strongly of burning plastic or rubber; my wife thought it was a tire based on the smell. During the whole ordeal(s), the car never actually seemed to RUN any differently/worse. From voltstats, the previous owner drove it nearly 100% on gasoline (go figure...), and their overall average was 40mpg. Since buying it on 10/28/18, it's now nearly at 59k mi, about 45-50% of those miles are EV, 100% have been HIGHLY enjoyable.
However, I'm worried about a few things: first, what do you think could be causing the car to run OK on gas if I'm cruising lightly between 25-65mph, but any faster and it works to hard and overheats (coolant temp in DIC jumps past 212F when problem starts), any slower and there's not enough airflow to cool it and it overheats (same jump in coolant temp seen)? I can easily replicate the stationary issue by running the car in Mountain Mode with the battery dead, to force the engine to "idle" while stationary. Second, do you think any long-lasting/other damage may have been done? I've emailed the service guys over there, who so far have been fantastic about fixing a few other little issues (missing wheel well liner, etc), but I haven't heard back since they're not open on the weekends. Any input is greatly appreciated!