Good evening Scotty. My 2014 4cyl Journey is acting up.  My wife loves it so we are hoping it's an easy fix.  We just got it about 6mo ago with about 200,000km and within about 2mo it ran up the temp gauge so we took it to a good local shop we trust.  They changed the thermostat housing [and I assume both stats were also part of the kit] and it ran great for about another 2-3mo.  The temp gauge held around center and the dash computer read around 100deg C give or take a few.

Now, the gauge starts climbing most times we drive.  It runs between half and 3/4 and usually on the high side of that.  The dash computer is reading usually between 118-125deg C and this has been getting worse.  A few weeks ago it was more between 110-117degC.

I don't see the overflow tank bubbling over or surging nor is there any noticeable leaks inside or outside of coolant, I have not added to it.  The oil level is fine.  The temps climb whether the AC or heat is on.  We can get the temps to drop somewhat by putting the heater on high or by lowering the RPMs.  It seems to run around 2k RPM when at highway speeds but when we cut that back a bit, it does lower the temp for a little time.

I would like your opinion please of possible areas to check.  I was going to call the shop to see if the thermostats [at least one of them] may be faulty out of the box?  But would you think something else is more likely?  Maybe cooling system needing a flush, or a bad heater core, or a radiator issue?

Thanks for your time to read through this, and for all the great content you keep giving to us.  Hope you can keep it up for some time yet.

Regards,

Travis May