Then, a few weeks later, we hit a rash of warm days and started seeing the Jeep constantly running above the 210-degree dash on the temp gauge. It already had what looked to be a two or three core copper brass radiator in it, so we performed a deep flush with some Prestone radiator flush and then swapped in a 180-degree thermostat. The Jeep was then OK on the highway, but at low speeds we started having issues. Rather than try to replace the radiator, we added these hood vents from Gen-Right Off Road. We like the look of the 5.9L Grand and wanted to mimic that. It definitely helped to get the heat out and make the Jeep run cooler in traffic and on the trail, but we are waiting for some very hot days to see how it really works.