OK Guys, Let's Play "What's This Noise"

Now, the sound is similar to a mid-pipe leak and is coming from near the engine bay. It sounds like it is right at the firewall. It is a low tick, not the sharp tick you get from the header gaskets when they go out and is most noticeable when accelerating or going up a hill. The higher the RPMs go, the less I can hear it, but that is probably just due to the exhaust volume. While idling it is still there, but not nearly as noticeable.

It started after installing a Bassani off road X-pipe and removing the AIR/thermactor system, and has lasted through a head/intake swap, two sets of headers, and a Pro-Chamber installation. It is NOT a leak, at least not one that is on the exhaust system. The original heads were on the car when it started, but it now has TFS TW heads with a Cobra intake, along with FMS 1.7 rockers and new lifters. The heads were capped in the back with bolts that threaded into where the thermactor tube used to go. The EGR valve and tube going to the header were also replaced. I have also removed the spout connector to see if it was timing, but it isn't.

Any ideas? This has seriously stumped me, and is getting quite frustrating.

Yeah. One was welded, the other I just used a hose with a bolt clamped in, it wasn't the problem.

95Vert383AOD said:

Check that the header bolts are tight had an issue where mine kept loosening. If not that then check where the header bolts to the midpipe. I just did recent exhaust work on my car and didnt even realize my driver one was loose. I have also seen noise due to a O2 sensor getting loose.

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Sound was there with the original headers, Summit shorty headers, and now with MAC longtubes. Even right after firing the car with new headers and gaskets the sound was there. Mid pipe would loosen before, but even after tightening the sound was there. The new MAC ProChamber seals tight and still the same problem. Checked the O2 sensors first when this started happening, but no luck.

95Vert383AOD said:

is it coming from under the valve cover?? like possibly a slightly loose rocker?? Or a lifter not pumping up like it should?

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Rockers are tight and the lifters are new. I checked them the last time I adjusted the valves just to make sure everything was pumping up and they were good.

91LX_5L said:

did you remove you EGR stuff? did you block the back of the heads?

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The heads were capped in the back with bolts that threaded into where the thermactor tube used to go.

earleys94gt said:

On what side of the engine is the "tick" coming from?

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It doesn't really come from a side. I jacked the car up and it sounds like something in the exhaust. Even the local exhaust guy was looking for leaks, then he concluded it was due to something sticking up into the exhaust flow, however there have been three different setups on the car and I doubt each one had something protruding enough to make the same sound.

91LX_5L said:

i had a tick noise too and funny as it sounds turned out to be my dipstick after installing my exhaust was not bolted on right and was vibrating, doubt it happened to you but worth a look, it sounded like a lifter or header leak.

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I just spent so much time wrestling with that dipstick to get it fit around the longtubes that I can say without a doubt that isn't it.

Thanks for the help so far guys, hopefully I can figure this damn thing out.