99+ Intake Manifold Leak???

Ok so I swapped out the intake on my 97 for the coveted 99+ version, and man what a pain. I think a lot had to do with the 20 degree weather, but it still proved tricky. Between leak injectors and broken vacuum lines it wasn't much fun.

But anyway here come the problems. First, it leaks. My idle is a little higher than normal, around 1000-1200 rpms. I've checked every vacuum hose and fitting, they're all straight. I also sprayed some carb cleaner where the gasket and head meet, and my idle drops significantly before shooting back up. So I'm guessing it's at the gasket. This leak in turn has a big effect on how the transmission acts (so it seems). The torque converter unlocks after the slightest release of the throttle, and the rpms jump up as I come to a stop. Almost like I'm downshifting, but it's an AW4??

Next is the fitment. Do I need the 99 header as well? My exhaust is the newer version already with the flex joints, however the back 2 studs don't even come close to touching the intake manifold. They have proper contact on the exhaust portion, but there is about 1/4 of an inch of space between the thick washer and the intake.

Any ideas??? I'm going to my buddies shop this Saturday to investigate so any tips or tricks are appreciated!

I am going to guess that you didn't replace the intake gasket because you did not remove the exhaust manifold. Am I right?

That is probably why it is leaking.

Nope. Took it off and put on a brand new OEM one at the same time. Even used some rtv copper on the exhaust manifold. Should I go back and do the same for the intake manifold?

DanMan2k06 said:

however the back 2 studs don't even come close to touching the intake manifold. They have proper contact on the exhaust portion, but there is about 1/4 of an inch of space between the thick washer and the intake.

Click to expand...

Are you saying the Intake flange is thicker than the exhaust flange and thus the dish washer hits the intake first & can't be tightened enough so it's contacting both the exhaust & the intake?

Check that one of the exhaust tubes isn't hitting the intake anywhere. I've seen a couple of other threads where someone with an aftermarket header complained that the 99+ intake and one or more of the rear header tubes interfered with each other.

check this one out: http://www.naxja.org/forum/showthread.php?t=84418

Yes that's exactly what I'm saying. It contacts the exhaust manifold, and not the intake. Almost like the intake is much smaller. It's not hitting the exhaust, and both LOOK to be sealed against the head, but clearly are not.