2020 Jeep Gladiator engine problems

“On May 27, 2026 at approximately 11:00 PM, my 2020 Jeep Gladiator Overland (VIN: [XXX] ) suffered catastrophic engine failure during normal operation at 78,190 miles. The alternator seized, causing the harmonic balancer (crankshaft damper) to fracture. The broken balancer fell into the engine block, causing extensive internal damage requiring complete engine replacement at significant cost. This failure sequence points to a design and/or manufacturing defect in the OEM alternator and/or its mounting system on the 3.6L Pentastar V6. A properly designed alternator should not seize with enough force to fracture the harmonic balancer and deposit debris into the engine block under normal operating conditions. The vehicle was not involved in any accident or operator abuse. It was being driven normally with no prior warning — no dashboard lights, no unusual sounds, no prior related mechanical issues. I request NHTSA investigate whether this failure pattern is systemic across 2020 Jeep Gladiator vehicles and other 3.6L Pentastar V6 platforms, including the Jeep Wrangler, Ram 1500, and Dodge Durango. Sudden complete engine failure at highway speeds is an immediate crash…”

“At 90k miles head gasket failed letting coolant in engine cylinders which was diagnosed and repaired by a Jeep dealer. At 130k miles engine light back on with dealer suggesting it is rocker arm/lifter failure with cylinders misfiring. At initial purchase of vehicle touchscreen would black out and restart. Dealer replaced with another touchscreen but issue still exists after warranty term.”

“Engine failure due to coolant leak: in December, 2025, vehicle was towed to dealership due to overheating engine. While driving home from work, Vehicle was exhibiting engine overheating including temperature warning lights, temperature gauge fluctuating from normal to extremely high, a strange sound coming from the front of the vehicle (almost like a fan was not working) and running rough, like a diesel idle. I immediately pulled the vehicle off to the side of the road & shut it off. (Fortunately engine didn’t seize or exhibit these symptoms while I was on the highway just minutes before) I called dealership & they said it needed to be towed in. After having my vehicle for 10 days, Dealership stated thermostat needed to be replaced. Vehicle then exhibited same symptoms a few weeks later along with a check engine light, vehicle is returned to dealership. Dealership NOW tells me they’ve “seen enough of these to know that it’s most likely going to need a left side cylinder head” due to coolant leak into the engine. I am now aware there have been multiple reports to NHTSA for similar issues and that a service bulletin has been issued to the dealerships for this…”

“My jeep has 140,000 mile engine oil has been changed on time every time. And the engine has cylinders that are missing and it's using antifreeze and riddles like a diesel from time to time. I looked it up and it seems to be a common problem with these engine and there has not been a recall for this. But funny thing is they make a repair kit for this issue. Why has this not been recalled yet it's on all the jeep forms. Even wright ups of fires after a while of driving in this condition.”

“My vehicle has a 3.6 pentastar engine. Around 75,000 miles the check engine light came on. I took it to the dealership to run diagnostics and find the problem. After completing the diagnostics the service tech informed me that is was an issue related to a TSB 09-011-25. This is a major manufacturing issue that causes engine failure. My engine needs to be replaced. This issue affects many vehicles in the Stellantis lineup and should be a recall. They have not made any effort to inform customers of this issue to have it inspected”

“The contact owns a 2020 Jeep Gladiator. The contact stated that while driving at approximately 40 MPH, the vehicle had suddenly started to vibrate and shake. The contact stated that the vehicle was maintaining its lane but was lurching from left to right. No warnings illuminated. The contact stated that she pulled off to the side of the road; however, when she turned the vehicle on, it would start shaking again. The contact stated that she would keep driving while the vehicle was shaking, and the shaking would eventually stop. The contact stated that the shaking was occurring at any speed and was also triggered when she would drive over any small bumps or dips in the road. The contact stated recently, while she was driving in traffic at approximately 10 MPH, the vehicle started to shake again, however, this time violently. The contact stated that at the time, it was raining. The contact stated that it felt like the vehicle had lifted up, and then she crashed into the guard rail on the driver's side front bumper. The contact stated that the bumper and an LED light bar attached to the front grill had made contact and were slightly damaged, and the driver's side…”