how much it will cost to replace the secondary timing chain

On a 2WD replacing the secondary t/chain is a 9 hour job the radiator is removed for easier axcess , Nisan radiator would cost approx $200 after market to $550 if you buy the radiator at the dealer.

This is a common problem, in fact there is a tsb from nissan for this, you need to replace both chains and tensioners to eliminate the noise, replacing the radiator might not be a bad idea even if it is not leaking because it is removed during the repair to gain access to timing chain cover, timing chain replacment w/ radiator runs 1400.00 at my shop, so their estimate seems fair-hope this was helpful. Ryan Mode Mode Automotive 858-361-4645