heater problems? hot engine? 03.5 g35. help?

[Nublet]

I noticed that when i drive my car for more than 30 minutes or so at high speeds, the engine heat seems to be coming thru my AC vents. i have all the AC acceories turned off. I can't seem to turn off that air re-cycle and the one that allows cold air to come in thru your engine without turning the actua l AC on. looks like one of them has to be on. but anyway, is this normal? it does get kinda warm when the windows are up, i can even feel the warm air coming thru the vents when i put my hands over them. Its as if the heater is on.

[C-Kwik]

It's normal. It seems that Nissan did a poor job with the climate systems on their cars. Either the heatercore is not isolated well enough or the vents are getting too much heat from other parts of the car. I noticed this feature most when I parked the car and got back in a short time later. I'm noticing a similar issue with my Titan to a lesser extent than the G35 had.

[Q45tech]

The has been the case for the 17 years Infiniti has been produced.............5-8F temperature rise from the ambient above the hood, usually correlates with 10-11F above radio weather report [measured in shade and above grass].