i'm not sure if i get this...a ticking sound?

have you crossed with the taliban lately?

from my experience, any leak coming from the exhaust manifold sounds more like a whistle. somtimes like a siren if its a higher compression engine.

i have the old exhaust manifolds from my 03 tundra (swapped them out with jba headers)
i can see that the flanges are not stationary, they actually move around like a seperate piece. i can see over time how that area could crack.

 

If you suspect an EM leak, get a mechanics stethoscope (or a piece of PVC pipe) and try to localize the leak. You can try to re-torque the flange nuts.

 

If you suspect an EM leak, get a mechanics stethoscope (or a piece of PVC pipe) and try to localize the leak. You can try to re-torque the flange nuts.

Cut a 4 foot piece of old garden hose, stick a small funnel in one end and hold it up to your right ear (save the left one for your cell phone) and move the other end of the hose around the exhaust manifold while the engine is running. You'll hear any leaks when you're close to them.
Watch out for the fan and belts running.:chug:

 

exhaust ticks

I had the exact same problem with a Z-28. Once I put headers on it the bolts would not stay tight and the gasket would get a path burned through it. That would cause the ticking you describe. Just wanted to remind you to check them really closely before you buy a new manifold. Plus it's a lot less work to change a gasket than the manifold. You can usually lean them back enough to slip a gasket in without breaking the bolts on the exhaust pipe. Hope this helps.

 

the ticking noise you are hearing is fairly common and most likely a cracked manifold tube ussually on the first cylinder tube and are most commonly on the passenger side bank. toyota has addressed the issue but wont help out with new parts if your warranty has expired. luckily i have not had a problem on my 2002, yet.... i would suggest a quality aftermarket header as a replacement as the manifolds parrallel the headers in price and the headers will compliment any add-ons you may have installed. i will suggest that if you do replace with headers that you have the ecm reporgramed to make full use of the new flow.

 

This is a bad Idea. Even the mechanics at toyota cannot get the aftermarket headers (including TRD) to seal for longer than 6 months. You will still have your exhaust leak, but I will say you will have a significant gain in performance though. I installed headers on my 04 tundra and would never do it again. Pain in the Butt!!!! with a leak still. I even used Percy Seal-4-Good gaskets to no avail. No offense to you toyotaman68, I'm just warning against the inevitable.

 

the ticking noise you are hearing is fairly common and most likely a cracked manifold tube ussually on the first cylinder tube and are most commonly on the passenger side bank. toyota has addressed the issue but wont help out with new parts if your warranty has expired. luckily i have not had a problem on my 2002, yet.... i would suggest a quality aftermarket header as a replacement as the manifolds parrallel the headers in price and the headers will compliment any add-ons you may have installed. i will suggest that if you do replace with headers that you have the ecm reporgramed to make full use of the new flow.

toyota had a tsb for the exhaust manifolds for the taco. but now on TIS i cant find it anymore.. even tho i use a different op code and get more time than the TSB.. im just wonder if you knew what happen to the TSB and why would it dissapear than show its obsolete

 

Toyotaman68 is correct, my 2001 had the same ticking sound. Took it to a local mechanic, they found a crack on the right side manifold. They pumped smoke into the exhaust pipe after the truck sat overnight and found the crack with no problems.