NHTSA Complaint #11462120 — 2021 JEEP GLADIATOR

When operating the vehicle under heavier loads (5%+ grades, towing even light trailers, higher highway speeds) vehicle loses power limiting speed to 15-50mph depending on how hot the water or oil temperature is. I have had this issue in ambient temperatures as low as 31°F while towing 4000lb up a steep incline, but will absolutely overheat if ambient temp is over 100°F. Vehicle must be left running during a fuel stop or heat soak caused by the vehicle is not running will prevent me from merging back on the highway at a safe speed....max speed is 50mph until the engine oil cools off. Air conditioner use as expected makes the problem worse. There are many threads going on the Jeep internet forums with many diesel equipped Jeep Wranglers and Gladiators having the same issues, so I know these aren't isolated incidents from my vehicle alone. If you were to search "Ecodiesel power derating as temps rise" on Google, you would see some discussion. Engine fan runs at full speed, coolant is full, and radiator/grill is clean/free of debris. I have owned this vehicle since new and have operated in many types of conditions/loads over the past 14 months 23,000 miles from 9°-126°F. The first time I had the issue was late May of 2021 (At approx 5,000 miles) and it has happened no less than 20 times since then. The only visual alarm is when coolant temp reaches 248° and the vehicle speed drops to 10mph. The gauge does not read linear........Meaning the vehicle is almost already overheated by the gauge shows the temp is rising. I can only assume the is intentionally programmed into the code by the vehicle manufacturer to make the operator feel like the high temps are normal. I have not had the vehicle inspected by the local dealer because in the past they were never able to duplicate the conditions in my opinion due to laziness or incompetence. I own an auto repair shop and know the problem to be an undersized cooling system which Chrysler does not have an approved fix for.