I have an LC9 in my Land Rover Discovery 2 (5.3L Gen 4). Around town, I?m at 200-210, even on 95 degree days in stop and go traffic. Going up the shorter, steep mountain roads here in Colorado, I get to 215-220. Going up I-70 (at 65mph and a steep grade), it quickly rises to 230 but drops pretty quickly when I turn around (even as low as 190 when coasting downhill). I know the stock GM ECT gauge goes all the way to 260 and GM doesn?t max out the second fan until 235 or so (in the stock tune) so I?m trying to understand if this is normal for Gen 4 truck motors or if something is wrong.
I have replaced the stock radiator with a 2-row aluminum version with dual fans and a shroud. Thermostat is a new 170-degree unit. Water pump is new AC Delco. Coolant is new and refilled with a vacuum system to get rid of air pockets. I also tested for a combustion leak (aka head gasket leak) and all is good there.