2021 Jeep Grand Cherokee engine problems

Filed Nov 5, 2026 · Engine · NJ

September 1: The vehicle triggered diagnostic trouble code P0306 (Cylinder 6 Misfire). It was immediately taken to an independent mechanic where the spark plugs were replaced to address the misfire. September 30: The engine suddenly refused to crank or start. The vehicle was towed back to the independent mechanic. The technician diagnosed a completely blown starter motor and noted thick white smoke billowing from the tailpipe upon replacement. Further testing revealed that engine coolant had flooded into Cylinder 6. Present: The vehicle was towed to an authorized Jeep Dealership for a comprehensive engine teardown. The dealership technicians confirmed that both the cylinder head and the engine block deck are permanently warped due to extreme localized thermal stress. Dealership advised coolant was not low and no codes on the computer to show that there was overheating occurring. All oil changes were done at the dealership and stellantis don't want to help with the replacement of the engine goodwill offered 10,500 digital imaging says no my fault I drove it overheating Coolant not low per dealership and no lights how was I to know it was overheating

Filed Oct 26, 2026 · Engine · OK

Oil Filter Housing/Oil Cooler Failure Causing Oil and Coolant Contamination, Serpentine Belt Failure, and Engine Overheating My 2021 Jeep Grand Cherokee Laredo E, equipped with the 3.6L Pentastar V6 engine, has developed a significant oil leak originating from the oil filter housing/oil cooler assembly. A mechanic has identified this assembly as the source of the oil leak and confirmed that its failure is allowing engine oil to mix with the coolant. In addition to internal oil and coolant contamination, engine oil is leaking externally onto surrounding engine components, potentially including the serpentine belt and pulley system. The vehicle recently experienced a complete serpentine belt failure while driving, resulting in engine overheating and requiring me to pull over immediately to prevent additional engine damage. I am concerned that oil leaking from the housing assembly may have contributed to the premature deterioration and failure of the serpentine belt. The oil contamination of the cooling system presents additional safety concerns, including reduced cooling efficiency, damage to cooling system components, and the possibility of severe engine damage or unexpected vehicle disablement. The combined risks of external oil leakage, internal coolant contamination, serpentine belt failure, and engine overheating create a potentially dangerous situation, particularly during highway driving. I am concerned that the oil filter housing/oil cooler assembly may have an underlying design or manufacturing defect. I am requesting that the federal safety agency investigate this issue in 2021 Jeep Grand Cherokee vehicles equipped with the 3.6L Pentastar engine and determine whether a safety recall or other corrective action is warranted.

Filed Sep 25, 2026 · Brakes, Engine · 46,116 miles · CA

The contact owns a 2021 Jeep Grand Cherokee. The contact stated that while driving at an undisclosed speed, there was large puff of smoke coming from the driver's side of the vehicle while coming to a stop. The contact became aware of a brake fluid leak, causing a complete loss of brake pressure and braking power. The brake fluid was leaking more when the brake pedal was depressed. The vehicle was towed to a local independent mechanic and the technicians discovered that the catalytic converter was melted, causing severe heat damage to the adjacent brake lines. The contact stated no other parts were damaged. The vehicle was towed to a dealer; however, the technicians were unable to duplicate the original failure. The dealer was unable to determine what caused the catalytic converter to collapse onto the heat shield near the brake lines. The contact stated that the dealer offered to repair the vehicle by rerouting the brake lines. The manufacturer was notified of the failure. The failure mileage was 46,116.

Filed May 14, 2026 · Engine · CA

-Thermostat -car died in traffic -not that I know of -it was diagnosed by the dealer -no warning lights or lamps -not that I’m aware if

Filed Apr 2, 2026 · Electrical, Engine · PA

This submission is an update to the federal safety agency Complaint #11727024. The vehicle continues to experience recurring engine overheating and misfire conditions. These issues have been previously diagnosed and are consistent with known manufacturer Technical Service Bulletins (TSBs) related to this engine. Despite this: The dealership has not performed the appropriate diagnostic protocol (including STAR testing) The manufacturer, Stellantis, closed my case without resolving the issue No repair or corrective action has been completed The vehicle remains in operation due to lack of manufacturer support. This condition presents a potential safety risk, including: Loss of power while driving Risk of engine failure or shutdown Increased risk during normal roadway operation The vehicle is regularly operated by my 17-year-old daughter, which increases concern regarding driver safety and reliability of the vehicle under these conditions. This situation reflects: A known defect documented by the manufacturer Failure of the dealer network to properly diagnose/repair Closure of a manufacturer case without resolution of a safety-related issue I am requesting that this complaint be reviewed as part of any broader pattern of similar failures and considered for further investigation.

Filed Apr 2, 2026 · Engine, Suspension · MO

BE ASVISED, THIS REPORT MAY BE INTERCEPTED, DELETED, HIDDEN, OR MODIFIED UPON RECEIVING. the federal safety agency Vehicle Safety Complaint Complainant: [XXX] [XXX] [XXX] Vehicle: 2021 Jeep Grand Cherokee ------------------------------------- SAFETY DEFECT COMPLAINT – POST-REPAIR VEHICLE CONDITION I am reporting a serious safety concern involving my vehicle following collision repairs performed by Gerber Collision & Glass under a claim handled by State Farm Insurance. After the repair, the vehicle began exhibiting multiple safety-related issues, including: - Steering instability and shaking - Engine performance issues and abnormal noise - HVAC malfunction - Persistent chemical and/or coolant odors - Physical symptoms while driving, including dizziness, lightheadedness, and shortness of breath I returned to the repair facility with photographic evidence showing parts with visible wear and damage that appear inconsistent with proper replacement. Despite this, no diagnostic evaluation was performed, and no corrective action was taken. The repair facility has refused to address the condition of these parts, and the insurer has refused to authorize further inspection. Additionally, there are discrepancies between the insurance estimate and the final repair invoice, raising concerns about whether the documented work matches what was actually performed, including work involving structural components such as the cradle/subframe. I believe this vehicle may be unsafe to operate and that the repair may have introduced or failed to correct conditions that pose a risk to driver safety. I request that this matter be reviewed as a potential safety defect related to post-collision repair. Sincerely, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Mar 25, 2026 · Electrical, Engine · PA

I am reporting a repeated safety-related issue involving my 2021 Jeep Cherokee Overland. The vehicle has experienced ongoing engine misfires and overheating, which create unsafe driving conditions. The issue presents as follows: -Engine begins to misfire, causing rough operation and shaking. -The check engine light flashes intermittently indicating active misfire. -Vehicle performance becomes inconsistent, with concern for loss of power while driving. -Vehicle experiencing coolant loss/overheating, concern for engine failure. These conditions create a serious safety risk, as the vehicle may lose power unexpectedly or become inoperable while driving. Multiple repair attempts have been made, including replacement of ignition components (coils and spark plugs) and other related service. The issue continues to recur, and the root cause has not been resolved. Despite repeated attempts to resolve the issue through the dealership and manufacturer, the problem persists and the vehicle remains unreliable. The manufacturer has not provided a resolution despite multiple attempts, and communication is unsuccessful I am submitting this complaint due to ongoing safety concerns and a lack of resolution.

Filed Jan 24, 2026 · Electrical, Engine · WI

This vehicle has ongoing issues with electrical systems. Any time temperature drops into negative digits the vehicle will drain both batteries to the point the auto is inoperable. Further jump starting the vehicle in a very low battery state is a futile venture. The issue leaves the vehicle and it's occupants stranded in sub-zero conditions.

Filed Jan 11, 2026 · Engine · MI

I am reporting a potential safety-related defect involving my Chrysler vehicle equipped with a V6 Pentastar engine. During a routine oil change a few weeks ago, I was informed by the service provider that my engine oil level was extremely low, despite the oil change being performed earlier than the recommended interval. This was alarming, as the vehicle had not shown any warning lights or obvious leaks. The service provider advised me that Chrysler vehicles with the V6 Pentastar engine have a known issue related to a defective engine seal that can cause excessive oil consumption. I was told that Chrysler is aware of this issue, that it has been the subject of class action lawsuits, but that it has not been formally recalled. I have since submitted my information to a class action settlement related to this issue but have not received any response. Due to the risk of engine damage, sudden failure, or safety hazards while driving, I believe this issue should be formally reviewed and documented by the federal safety agency. I am submitting this report to help document a potentially widespread defect that may affect vehicle safety and to ensure appropriate action is taken to protect consumers.

Filed Nov 16, 2025 · Engine, Fuel system · NJ

The issue is in starting the vehicle. When I push the start button, the vehicle starts, but the engine continues to turn without stopping and turning over. I then push the start button again to turn off the engine and make another attempt, and then it will start normally. This has happened several times in the last few weeks. Also, sometimes when you push the start button, nothing happens, and the vehicle will not start. It takes a second attempt to start normally