Well just put on around 1000 miles and craziest thing I’m now smelling tasting exhaust and eyes I have become irritated some? After a few weeks driving with this issue I actually turned off the heater today and fan and it seemed better. Am I the only one who is experiencing this issue? Two things i’m guessing faulty heater core or head gasket problem even though the coolant seems to be level. I noticed on the coolant overflow tank there was a mark which indicates level and when it’s hot or cold it’s hitting the mark and then if driving temperature is reached it changes. But it is consistent depending on if it’s hot or cold and where the line on the overflow tank is. I haven’t taken it in for service yet but I will have to soon because very hard to drive with bad taste in mouth. I now have around 1800 miles brand new truck V6 automatic.