I am the original poster(If that's what "OP" means-I had to google it) and yes I am still here. I appreciate all the helpful comments and feedback I have been getting from this forum. I have been passing them onto the mechanics at Ford. I haven't been posting, because there has been no change. Car is still at dealership as they try to figure out what is going on. Thanks for your post
I've been watching
this thread pretty closely over at the Explorer Forum, and it sounds like you've got the exact same problem - with a similar initial response from Ford.
The
Explorer TSB details a couple possible fixes. In order of attempt: Update HVAC computer to latest software; inspect all possible holes and seams for improper sealant, apply sealant as necessary; install exhaust tips with an internal turn-down so that exhaust exits the bottom, but still keeps the shiny straight exit look.
When you are in normal mode the fresh air that comes in, exits through the vents behind the tail lights. When you are in recirc mode if the pressure in the vehicle is lower it might allow the vents to pull in exhaust.
That seems to make sense, but on the explorers, the TSB was looking at ALL possible holes, but left the "air extractors" alone except to seal them for a pressure test. My understanding is that these vents are only supposed to let any positive pressure out, and in Recirc mode, there's supposed to be negative pressure, but I wonder if they just aren't sealing properly...
In another post, you mentioned that you hadn't experienced it. Put the rear AC off completely, put your front AC on recirculate (with MAX fan setting) and do a long WOT run, such as pulling onto the interstate. That seems to be a sure-fire way to get it to show up in the Explorers.