[mgarblik]

Most likely a goofy thermostat is the issue. Been seeing more and more inconsistent, malfunctioning thermostats in the last 3-5 years than in my entire career. To try and combat this, I tried several of the safe-T stat type thermostats. That did not solve the issue. Just ended up with them latched in the open position. So that's not a fix. If a fresh thermostat doesn't seem to fix it, consider purchasing an infra-red temperature gun for better diagnosis. They are a handy little tool and Harbor Freight has decent ones for around $40.00. A good working cooling system should have about a 20 degree drop on the inlet hose, (lower) vs the upper hose once up to temperature. I doubt the water pump is the problem in this situation. If you have a quality pump, cast impeller, decent plate clearance, good, tight fitting rubber sleeves in the transfer tubes, there really isn't anything else in there to give you trouble.

[Squidward]

Originally Posted by mgarblik

If a fresh thermostat doesn't seem to fix it, consider purchasing an infra-red temperature gun for better diagnosis. They are a handy little tool and Harbor Freight has decent ones for around $40.00. A good working cooling system should have about a 20 degree drop on the inlet hose, (lower) vs the upper hose once up to temperature. I doubt the water pump is the problem in this situation.

I got this one, worked well:
https://www.amazon.com/dp/B0CH6LKBSZ...fed_asin_title

I did the temp sensor cal with it on my FiTech, and it matches within 2-3 degrees of my digital cluster temp sensor, both located in the coolant crossover.

Interesting you mentioned the temp deltas. I would like to start collecting some IR data for inlet/outlet temps on various components. It'd be nice to know what expected temp deltas should be for a good working system. When it came to troubleshooting these issues, someone could throw $19 at an IR gun, and get real performance data before throwing $$$ at new pump/radiator/fan/deluxe tstat. I've personally taken that boat ride before.