I have new from front to back exhaust. No leaks at all and yet when i turn my heater on i get fumes inside the car. Any ideas. Ive even tried covering up the vent infront of the windshield and no help. And my tips come out the back about 3".

 

I have the same problem, I found out that if I turn off the fan when I'm approaching a stop, the fumes don't come in.

 

Yep thats what i do too but even town driving i get some fumes.

 

Your header/manifold bolts tight? How about the y pipe, those tight too?

 

Look up at your evaporator housing from underneath.

You'll probably find that it's crumbled to dust right where it's closest to the manifold / header; and underhood air is coming in through the hole. The hole is probably big enough to stick your fist through.

Eeeezy enough to pop the evap hsg completely off and fiberglass it over.

 

I will check the evaporator housing. My exhaust is all nee from manifolds back so no leaks ther at all

 

Thanks guys my evaporator was cracked. I fixed it and no more fumes

 

I was getting fumes a few days ago after turning on the AC. I found out the problem was that I didn't have a hood to cowl seal. All the air for the AC and the Heater gets sucked in from the cowl or the area where the wipers are. Fumes were being sucked in between the crack with the missing seal. For anyone who wants to know a simple solution to a reducing or elimination fumes in the cabin, make sure you have a cowl to hood seal.