Exaust smell in cab

[Mackie007]

Seems to be getting sucked in through the heater. I started using the heater this season about 2 weeks ago. Noticed a strong exaust smell in the cab after warming the truck up for just a few minutes. While driving the smell seem's to go away, but when stopped & idling for any length of time, I have to turn the heater fan off or get fumigated.



I'm going to try to trace it down this weekend. So far I've given a visual inspection under the hood, as well as tightened the turbo & exaust manifold bolts. But none of that has helped.



Any ideas?



Thanks,



Mac