I have a 2000 F350 with a 2V V10, 169,000 and change on the clock. Mostly stock, only aftermarket "upgrade" is an Air Raid cold air intake. My truck has had a mild exhaust manifold tick when you get on the gas, it's been there ever since I purchased it.
While chasing down a bad coil pack, I decided to do spark plugs while I was in there. I just had the threads strip out in my #8 cylinder while doing spark plugs, so I pulled the intake and installed a helicoil insert into the head. While the intake was off, I went through and replaced a few things that haven't been done in the life of the truck. I did the intake Gaskets that snap into the head, and the throttle body Gaskets. I also removed the oil valley type deal that's bolted to the bottom of the intake and replaced those Gaskets. I replaced my throttle position sensor (broke that while removing throttle body, whoops) and my thermostat. Also did fuel injector o rings.

I got the truck running and driving again, engine runs great now. Only problem is, I have a NEW noise. While under acceleration, I get a higher pitched whistle that changes in volume and pitch with my exhaust manifold leak. It almost sounds like it's under the dash board. It only happens in the 3-4K rpm range, and it doesn't happen all the time. Also, I cannot recreate it while parked and revving the engine, just like the exhaust leak. Does anybody know what could be ticking now? I torqued all the bolts down in order and according to fords specifications. Any help would be greatly appreciated.

 

Any biters? The noise hasn't gone away yet, it gets harder to hear when the truck is up to temp, but that might be coincidence. Anybody ever have problem with throttle body or intake Gaskets not sealing correctly?