Hello,
So I posted previously about high idle on a 4.9 assuming it was a vacuum leak. It was...mostly! I tested with cigar smoke thru the brake line. Works.. The intake was leaking like crazy. I tightened down on the bolts as much as possible. Now the truck idles noticeably lower but still high. It may be that the intake is still leakinga bit. Do I need a sealant here or did I get a cheap gasket? Coulda swore the box said Felpro. Interestingly, the truck kicks down to about where it belongs but then creeps back up after a second or two. I would appreciate your advice especially about the sealant. Tanks

 

Stick to one thread for the same issue......

My previous response: https://www.ford-trucks.com/forums/1...l#post16929776