Leaky exhaust manifold?

[vainot4u]

Hey everyone was wondering about this today..

I pulled my 94 Formula out of the garage the other day and noticed a tick/knock sound. My first inclination was possible noisy/bad lifter/rocker. But then I noticed it was a bit louder than a lifter so then I started thinking maybe a spun rod bearing or a rod knock. Knowing that the car was running fine last time I parked it I was bit perplexed by this. I pulled the car back into the garage and began to tear down the valve cover to get a look at the valve train. After opening the valve cover I started the car and watched the valves all working flawless, and the sound was gone...HUH? How could the sound be gone all the sudden?? While I was inspecting the valve train I had my head in the engine compartment, and got blasted with a sudden poof of exhaust gases, which came from the header. OK so now I am confused...I call my "mechanic" buddy and talk to him for a while and he says that he had an 86 T/A that had an exhaust manifold leak and it sounded exactly like what I am describing. Does any one else have experience with this? Do I really only need to replace my mani and call it a day? I'd hate to have to tear down the motor already as I just bought the car not too long ago...

Little details on the car:
94 Firebird Formula LT1/6 Speed
Stock manifolds with EGR delete
Stock y
Catless
Flowmaster cat back
Most of the rest of the car is stock

[97firehawk]

I had a few header bolts back out it made a horrible noise I swear I blew it up till I realized what happend I have some reusable header gaskets so i tightened them up and was good to go .

[2EVUL4U]

I had a few header bolts back out it made a horrible noise I swear I blew it up till I realized what happend I have some reusable header gaskets so i tightened them up and was good to go .

What he said ... Probably should check the bolts, first. If that doesn't solve it, you may have to get some new header/exhaust manifold gaskets ... That is, as long as you don't have a crack or some other leak from the manifold itself. Don't know how you deleted the EGR, or if you left the air-pump tubes attached to the manifolds.

[vainot4u]

Thanks guys did some more digging today, looks like the gasket is toast possibly the mani too. The leaks are coming from 2 spots I can see, the first is where the previous owner did the EGR delete where it attaches to the header, the second and most prevalent is on the rear most section of the header closest to the firewall, when I rev the motor a blast of exhaust gas comes out of there.

I think I am going to try and get my hands on some long tube headers and just replace the stock headers, at the same time I'll replace the gaskets (obviously), and since I'll probably be buying ones that don't even have EGR ports on it that won't be a concern. For now the car is gonna sit, I like to error on the side of caution. Once I replace the headers if the noise is gone then cool, otherwise I'll know I have more work to do.