exhaust manifold leak

i have always had a sound coming from my engine like a cracked or leaking manifold. kind of a ticking sound that get louder and faster with engine rpm. i always assumed it was a cracked exhaust manifold but when i looked at the manifold the other day it appears that the manifold bolt that is closest to the front bottom of the engine is actually missing. there is just a hole were it should be??? is there actually supposed to be a bolt there? i'm hoping putting a new bolt in there will get rid of the leak. any exhaust guru's have an opinion on this? thanks:rof:

it could have sheared off and left some in there. if thats the case, its a pain in the arse to remove and replace.

I am missing the exact same bolt on my '92. Mine sort of sounds like a diesel engine at time to time.

Mine did the same thing, but at the rear towards the firewall. There is a Stud at these locations. Mine broke off inside the head, and left nasty traces of itself in the head. I had to take mine to a machine shop and they ended up putting a helicoil in there and now everything is great. Its a big job, but well worth it.

Yep, it's should be a stud with a nut and they do commonly break off. If you're lucky, it just fell out.

This also happens to the 2.5L engine. We spend all day on the YJ pulling the manifolds and getting the stud out of the head. I've read that using a reverse drill bit can aid in removal. We used a centering bit and an easy out.

It is possible (but unlikely) that the screw or stud fell out. The holes are threaded 3/8"-16, and I think the underhead length on the screws is 1-1/4"

Note that you'll require the funky "dish" washers for these fasteners. Why? Because most of them have to clamp down on a chunk of aluminum and a chunk of iron - and aluminum expands twice as much as iron does (iron at .000006"/in/*F, aluminum at .000012"/in/*F.) This will work to unscrew the screws - and the washers are supposed to help prevent that by having some "give" before it gets to the screw. If you can't find dish washers, replace with Belleville spring washers (they're cone-shaped springs used as washers, and for much the same purpose.)