Unusual Vacuum Leak 2008 Ford Explorer 4.6L V8

Found a vacuum leak on the intake manifold runner on my 2008 Mercury Mountaineer 4.6L V8.
Symptoms and fix:
I started having issues around 95,000 miles. I kept getting random misfires, enough to occasionally throw a check engine. Checked my long term fuel trim (LTFT) and it was over 15 on both banks. I struggled forever to find the source of my vacuum leak that was causing a high LTFT, when I finally found the leak from the video. A new intake manifold brought the LTFT back to the 4-7 range. Not perfect, but the engine stopped randomly misfiring. I replaced the intake manifold at 110,000 miles.

[@MAbid-zt7nm]

I explorer 2008 4.0 v6.rough idle at

[@tone2259]

What is your car doing that you decided to check for a vacuum leak?

[@angeloportacio2634]

I feel like I might be having this problem on my 2006 explorer 4.6 because I had a Mis fire change the plugs good swapped coils good checked maf and pcv good did a compression test good so basically a needle in the hay stack on something you would expect to be simple to find and fix.

[@Juanito548]

Have you noticed that the intake runners/butterflies tick when accelerating? was the new intake quieter?

[@alfredotorres9930]

I have a 2006 Ford explorer 4.6 Eddie Bauer and I have a p0303 misfire on 3 code I changed my coils and my fuel injectors and plug on 3 but someone said I might have a vacuum leak could it be something like this ?

[@chrismccann5380]

I know this is old.. I seem to have the same issue on my Moutaineer, I get the lean codes, no misfires though. So your fix was a new intake manifold?

[@angeloportacio2634]

If I don't find the leak its going to the dealer😟

[@MrPami9899]

Does a bad gasket do that??or is it cracked

[@Texas_Road_Warrior]

The only thing that pisses my off about the gen 4 explorers 06-10 4.6 3v is there is absolutely 0% aftermarket support... it’s absolutely worthless to modify these things! I can’t find a intake manifold, it’s plastic it’s bound to crack ( mine already is it’s slowly using coolant but there’s visible leaks ) the only aftermarket thing is a cold air intake... it’s beyond stupid... and if you search 2006 Ford Explorer 4.6 intake manifold, the only thing that comes up is the older 4.6 intakes that have the throttle bodies on top... I mean I can buy one from ford for 600$ but why? I can buy the ford racing intake for 600$... theres WAY more support for the crappy v6s than the v8 its absurd!