Thermostat and ticking..fixed but new issue
 

Any suggestions,
Thank you for your time. I live in Southern Arizona...the really hot place...It was 105° today. Any way I have been having issues with (questionable lifter noise,ticking )defective expansion tanks, and thermostats (bypass was sticking) .in order to stop this problem I followed instructions on line to install a inline thermoatat. History prior to the install I had a overheating event that caused my 04 discovery to start ticking.
After installing the inline set up and getting rid of the bypass hose all of my problems have seemed to disappear. The ticking continued for one day. Over heating stopped, and my rig has new found horse power.
2 questions.
1. I am using a 180°t stat as recommended is that good for AZ or should i reduce to 160.
2. Now that I am running cooler I have thrown 2 codes PO430 and PO126 could running to cold cause this. Or the expansion tank leak that wet everything cause this. PO 430 has not shown up every time and 126 shows up every cold start morning only.
Tank was replaced and working fine now 4 tanks and 3 stats later.
Please Help,

John Glenn[/QUOTE]