[TheRoad64]

I have a 93 Formula with a severe miss that has developed over the past few months. Doesnt throw any codes, but has a bad misfire on two cylinders on the passenger side throughout the rpm range.

Before the miss set in, I noticed an exhaust leak that grew progressively worse , which I traced to the passenger side exhaust manifold, above the 02 sensor but not the manifold gaskets. It wasnt major so I ignored it. Then she started missing, first only when the car was hot, then all the time.

I'm 99% sure its a cracked exhaust manifold, and am wondering if this could cause a valvetrain issue (burned/bent valves).

 

[undergroundpred]

I have the exact same thing going on with my 1994 Caprice 5.7...This is my very 1st comment & this is my story: I bought the car last year of a mechanic in TX, It originally had a L99 4.3 V8. They replaced it w/ a LT1 but didn't change out the computer & wiring harness. The car had multiple exhaust leaks and had a very high Idle. I had to replace the ECM/PCM new exhaust from the cats back, and a new exhaust manifold gasket. Now, I hear a "Chat, chat, chat, chat" noise when I drive + it lacks power BAD. I had to drive from TX to Missouri in Sept 2010 and a round trip to TX & back to MO. My question is, did I ruin the heads? How would I know? I believe I need a new exhaust Manifold also on the right side.

 

[Viper]

If you find a crack in the exhaust manifold, you can repair it with JB weld I've repaired one on my 64 Chevy 292 manifold. The epoxy boils bubbles and hardens like a solder or soft weld. Better than having to pull the manifold and stick weld with silver rod until a replacement is available. Ticking is an exhaust leak. The sound with low power could be a blown head gasket. Does it overheat is there any oil in coolant coolant in oil? Run a compression test on the side with the sound I think you'll find the problem.