Clicking noise?

Hey, live in minnesota and its pretty cold up here. Anyways, it always happens when i turn it on. It's my dad's tundra, and I drive it too. Its the 4.7 V8 i-Force motor. Anyways, everytime i start it, there's a clicking noise coming from the engine, kinda sounds like the pistons, but it aint becuase i know how that would sound like. You can also hear it while driving around 10-35 mph, but after that its all good. Just wondering what it is. It has 65,xxx miles on it so far, probably take it to Toyota to check it even though it may cost alot.