I had just driven about 250 miles and was going up a steep grade travelling about 85 MPH when I noticed smoke in my rear view view mirror. I looked in my side mirror and black smoke was seemingly coming from the exhaust. The car was not overheating and the engine light did not come on I did not notice any type of smell. I lowered my speed to 65 MPH and turned off the air conditioner for a minute or two (it was about 95 degrees outside). The smoke subsided so I turned the A/C on and increased the speed to 70 and it smoked again. I repeated the same and smoke went away. I had cleared the grade by this time so continued to 75 with the A/C with no more smoke.
Do you have any ideas on what would cause the smoke? I have never noticed smoke coming from the exhaust before.
Monday, July 6th, 2020 AT 5:10 PM
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