I purchased a new exhaust manifold for my 93 from 1 A Auto. After pulling the Thunder it appears the manifold that is on there is 1 of the newer styles with the flex joint. I'm thinking my exhaust manifold may not be cracked or leaking it may just be a loud exhaust system. Is there a way to test if the exhaust manifold is cracked or not
Black 1993 YJ 4.0, 5 Speed
Slowly but surely getting better and better. Trailer build soon!!
I don't know exactly how to but you may look into using smoke. May just be a technique used to find vacuum leaks, maybe someone else could shed light.
Do a Seafoam treatment; you can clean up the carbon deposits and generate smoke for the leak test. Have someone cover the tailpipe with their shoe with the engine running; it will force more exhaust gas out of the leak.
You can do it with a cigarette or an insense stick. Just look for the smoke being push by a leak. If you had a diagnostic ttol that could read the O2 sensor voltage you would monitor the O2 sensor and spray with carb cleaner and look for the voltage spikes.
One trick I have used in the past is to take a 4' - 6' length of 1/4" tubing, insert one end in your ear and use the other end as an audible "sniffer" to test around the joints of the manifold. Once you find the spot, you will be able to hear the noise through the hose. Cheap and dirty stethoscope. Be wary of fans and belts when using this techniques, though.