Originally Posted by Prospeeder

Its just because 15w40 oil is so thick cold it stays in the tensioner better. There is no damage or wear happening from the brief noise of the tensioner, any manufacture will tell you its 100% normal to hear some chain noise on startup. If it persists longer than say 4-5 seconds I would say its worn out and should be replaced. I had one 2.8 that made the noise for like 10 seconds then went silent. I suggested replacement to the customer before total failure, which he did. If you have rather warm climate all year round should be no problem using 15w40 oil. I wouldnt use it if it dips below 0 lol but I suppose most diesel trucks work just fine with it.

Originally Posted by SloopJohnB@mac.com

Arguably noise is normal with wear, but on a new engine you won't hear it.
I didn't hear it on my 2K4.2 until about 130K miles, and I still don't hear any startup noise on my 02S6 at 140K miles (103K on this engine, replaced it at 88K with a 51K engine). If there is startup noise, the solenoid-operated valve in the cam chain tensioner is leaking down between startups.

If the plastic shoes aren't worn badly and the noise stops with engine startup and oil pressure (which could be another issue) there's probably no need to replace the tensioners.