my 05 tundra with the 4.0 and 6 speed tick's i found that if you fill it with oil to the full spot it does it not as loud, the tech i talked to when i bought it said the majority of 4.0s tick because of the vvit.

 

Mine has a tick, although not loud enough to be noticable with the hood closed. I figure it's normal valvetrain noise.

If your noise is valvetrain noise and it happens to be because the valves need adjusting, then you shouldn't hesitate to have it fixed. If you delay, it could cause damage.

I would either go to another dealer or contact Toyota directly if this dealer isn't taking your problem seriously.

 

The 4runner i just bought had a slight tick in it and 197k miles.I swapped it all over to synthetic(amsoil) .ive got 203 on it now still no ticking.
Also my 1999 z71 has had a tick init i swapped it over and it went away also.

 

The injectors can make substantial ticking noise. Its a function of wear and fuel pressure. Additionally, valve adjustment is critical for the first 10k miles.
The reason is that new engines wear in and when moving parts under pressure finally seat, usually clearances are created. Have you had the valves adjusted and injectors listened to with a scope. Between the two, the problem should be found. If not, its likely in the exhaust though unlikely the cause.

My $0.02