Originally Posted by flynavy812

This issue is so unbelievably frustrating because it’s not every single time I turn the truck on either. Probably going to return the machine too.

Originally Posted by digitaltrucker

Last month as a shot in the dark before my warranty (ESP) expires, I took my truck in and complained about the odor that has been around a long time. Dealership said I had a leak in the evap core and replaced it. I never expected that, and my AC was working as poorly as it always had. I think they did me a favor!

Originally Posted by flynavy812

Any idea if that’s a hard leak to check for? I had a pretty bad experience with dash replacement so I’m not too keen on letting them tear it apart again.

Originally Posted by pjband

I have a friend with a 15 and a co worker with a 18. They both complain of this. I have a 16 and use the air all summer. Most of the time forgetting to turn off anything. And have never experienced this. I have parked my truck in my drive on a hill with the nose down since new. They both are the opposite with nose uphill. Could this have anything to do with me not experiencing this oder? I feel bad for them.I have smelled both interior. It can get realy bad. I have helped both of them search for wet spots in the carpet. Spray thier vents. It is almost always there.

Originally Posted by Wanna Ride

Interesting theory. I currently own, and have owned, several F150s ranging from 2011 to 2018. I’ve heard several stories about others experiencing this issue, but I fortunately never have, on any of my trucks. And all of mine get parked facing slightly uphill, about a foot higher than the rear.

Originally Posted by mopar1970

The drain is at the back? I usually park on my driveway and have a slight front up angle.

Originally Posted by Wanna Ride

Interesting theory. I currently own, and have owned, several F150s ranging from 2011 to 2018. I’ve heard several stories about others experiencing this issue, but I fortunately never have, on any of my trucks. And all of mine get parked facing slightly uphill, about a foot higher than the rear.

Originally Posted by mopar1970

The drain is at the back? I usually park on my driveway and have a slight front up angle.

Originally Posted by pjband

well this debunks my theory. I'm nose down all the time. They are level or nose up.

Originally Posted by Wanna Ride

Your theory may still be correct, with some other variable that we’re not realizing. As much as I’ve heard about this issue, I’d still be interested in knowing what the problem is. It’s obvious that something’s causing it, we just don’t know for certain yet.

I had a Firebird a couple decades ago that would randomly do this, like once or twice a year. Never could find out what the source was.