Air cleaner bad design back keys left unengaged.
 

It’s easy to see how someone or some mechanics could leave the back of the air cleaner open and clip the front, I bet 2 out of 3 are like that right now! Check yours and report if it’s closed or open.

Air Box Hold-Down Clips
 

The 95 MERC has TWO Hold-Down Clips on the Air Box, as do ALL '92-'98 Grand Marquis, Crown Vics, and Lincoln Town Cars.
If all of the Hold-Down Clips are not fastened, it's not the designer's fault.
Somebody did sloppy work -- that's why we check this stuff.
https://cimg5.ibsrv.net/gimg/www.mer...4410eddba9.jpg
Classic Style -- Modern Comfort