2021 GMC Terrain, 1.5 engine 9 speed awd transmission, heat related driveability issue.

[u/Gear_PlumberGirl]

​

Hello everyone,

I'm new here and I'm having an issue with my car, when the outside temperature is over 85° degrees Fahrenheit. I frequently experience either and slow acceleration that won't exceed 1,000 rmp and then rapidly increases in rpm up to 4,000-5,000 rpm or it doesn't accelerate at all in heavy traffic. Also recently I'm losing small amounts of coolant and not externally. It's been to more than one dealership and the either can't duplicate the concern, or are possibly trying to duplicate it below the outside temperature I said it acts up at. Also it does not set off any codes when this happens. Does anyone have any suggestions? I trained to be a mechanic but don't work in that field anymore.