Actually, looking closer, it might be the plenum boot, which I missed because it's covered in crud. If you wash it, it will be the bright orange thing:lol:. I guess there's a chance it's the HPO lines, but it would come out with some force, and a small hole wouldn't stay small for long. How long does it take to get that cruddy?
I haven't cleaned it and it's been doing it for about a month ~3,000 miles.
Plenum boot makes sense. Right around the time this started, I began noticing a new hissing sound anytime I got over 8 psi of boost. I first heard the hiss when I was towing my skid steer on the gooseneck and climbing up a cloverleaf off ramp.
It was such a new sound that I pulled over to check things out.
I'll get out there in the morning and get everything cleaned up. Currently, I am losing about a quart every 2,500 miles.