2008 Chevy Colorado Ticking Noise at Startup

In have a 08 Chevy Colorado that actually has the 3.7, 5 cylinder engine. There is a ticking noise that reminds me of when your car has either a weak oil pump, worn lifters, etc. Until you get oil pressure.
This happens at every cold start or whenever the
vehicle has sat for at least thirty minutes. It has done it since the day I got the truck. I thought that maybe it would go away as the truck broke in but it hasn't. I recently took it back to the dealer. The service advisor said that it was "probably normal", but
they would have a technician check it out. They reached the conclusion that I needed an oil change. Yeah, on a new truck with 4000 miles on it. I went and picked it up. I did go ahead and change the oil.
Didn't solve anything, still clatters for a second or so when it starts up. A few days later I get a call from a customer service rep from the dealership wanting to know how I was treated and how come I had refused the oil change. I told her I was treated fine, but that if that oil change was the technicians response to my problem, I sure wouldn't feel comfortable with them even changing the oil on my vehicle. She asked me what I think should have been done and I said that some sort of testing on the oil pressure should have been done. To shorten this saga, she then went through scheduling me to bring the truck back and to have the techs check it again. I did this 2 days ago. They still have the truck, they have done nothing. They say they do not have the necessary tool to do the oil pressure test, but that it is on the way. They say a tech has listen to it at start-up and all that he hears is the "normal sound that that engine makes. That sound is from the timing belt tensioner, that makes a noise until the oil pressure builds up."What do you guys think?