Exhaust inspection question

[GotWood]

I have a bad leak at the manifold on my yj. I think it is the manifold gasket but I have had some prob from where the manifold connects to the exhaust pipe. What is a trick to pinpoint the leak? I have used a dow rod to check for knocks in the motor or finding a bad pully, but what works for checking for the exhaust leak?

 

[jeepman13]

old trick i learned it to pull off a vacuum line and place it in a pint of tranny oil while running. let the vacuum suck up some of the oil (just a couple of ounces) and the engine will start smoking away. easy to spot a leak at that point and it wont damage the engine if it's just a little bit.

 

[jeepman13]

I have had some prob from where the manifold connects to the exhaust pipe.

probably a cracked manifold. common problem with stock 4.0L exhaust manifolds.