Normal thermostat operation
 

With slightly cooler fall temps (40-50 F in the morning) I'm seeing my CHT on my scangauge 'pausing', shall we say at around 170-175 degrees if I'm sitting at an idle at a light. If I'm driving normally, it continues to heat up to normal operating temps of 220-230. Sometimes I notice that it even looses a few degrees at an idle.
It feels to me like it would not heat up above 170-175 at an idle no matter how long I let it sit.
Maybe I'll just try letting it sit and idle to see if it ever goes above that temp. It just seems like maybe the thermostat isn't closed all the way or opening prematurely.
Anyone else seen this? Or could someone try just letting your FEH idle when your around 170 F during warmup and let me know if CHT continues to climb even at an idle.
At ~$300-350 for thermostat replacement (and also getting the coolant flushed at the same time) I don't want to waste the money if this seems like normal operation.