First I will remove the OIL HEAT from the radiator

AFCO Stacked Plate Oil Coolers - Speedway Motors, America's Oldest Speed Shop
Run it in the sprint car

Next I will remove the transmission heat from the radiator

Aluminum Heatsink Transmission Cooler, 12 Inch - Speedway Motors, America's Oldest Speed Shop

And if it still gives me a problem then

Griffin Aluminum Racing Radiator, Double Row Core - Speedway Motors, America's Oldest Speed Shop

Then ADD for more cooling of the A/C
Single 14 Inch Fan Shroud Combo, 15 W x 18 H - Speedway Motors, America's Oldest Speed Shop

Then take 30% off racers net and you got an I DARE YOU TO OVERHEAT D1

For now I am in the cleaning stage of a NON OVERHEATING D1 that only shows up on the Ultra Gauge but when scanning the engine with an IR it is 10 deg lower.

 

Mr. George,

I have found looking at mine with several IR thermometers that temp sent to OBDII may not match any spot exactly on engine or radiator or hose or the thermostat housing the hose attaches to. I even took my coolant temp sensor out and used emery cloth to clean it up, removing any scale.

I run with the oil cooler and tranny coolers (rad mounted and towel bar ahead of condenser). I run a $10 180 F stat, spring side inside the block, jiggle device at 12:00. I run a larger than stock fan (donor = 2000 Blazer). I run a Blazer fan clutch (should not make any difference at highway speed. My copper and brass stock radiator was rodded out, and hot acid flushed.

178 - 183 highway, maybe get to 187 if 70 mph (i don't have too many expressways near me). With AC on. 100 miles south of you.

I think trying to depend on an IR for exact repeatable temperatures, with hot air blowing around, might be a little bit thrown off by that.

IMHO these other devices will also reduce temp, but you may not need all that to achieve lower temps. What does the Ultra Gauge say you are doing these days?

 

The DI radiator is 3 row.

 

yep, pretty good to start with.

 

Ultra Gauges are now mounted in ALL the Rovers.
All reading TODAY in a 20 mile loop and a stop to idle for 5 min then off again
P38 Normal running A/C on 45 to 50 mph 194 deg Stop and Idle 206 deg back to speed 196 then after a short distance 194.
P38, Rebuilt Motor 100% new cooling system including clamps 195 stat

98 D1 Normal running A/C on 45 to 50 mph 189 deg Stop and Idle 214 deg back to speed 206 then after a short distance 204.
NO a/c and the same loop
45 to 50 mph 191 deg Stop and Idle 199 deg back to speed 190 then after a short distance 188. 180 deg stat.
New Stat, replaced fans everything else checked out as working fine. Camera in Radiator showed VERY little gunk if any. Got the junk put blown out of the fins and a proper level with 50/50 and Royal Purple.
Noticed that the cap on the expansion tank was rated at 18 PSI but the replacement on line is for 15 PSI.
Also saw that the transmission cooler is painted BLACK and the fins ARE NOT silver which technically should not remove heat as fast.
Other than all that it is sitting in the shop waiting to get the window seals replaced to stop the flood.