2018 Jeep Grand Cherokee: misfire or rough idle

Filed Jun 17, 2026 · Engine · WI

* Upon normal driving the vehicle suddenly began to run rough. At that point the engine light came on and began flashing. Yes, it is available for inspection * I was traveling at highway speeds with my two young son's in the vehicle, when out of nowhere we experienced a major loss in power, Forcing us to get to the far right lane and off on the next exit. * The problem has been Confirmed (Passenger Side intake camshaft has 5 out of 6 lobes significantly worn off. .119" of material missing as well as 2 holes on cylinder 6 piston. * It was inspected by and independent mechanic who discovered the damage to the camshafts and the piston. It was suggested that I return the vehicle to the dealer as it would be needing a new motor seeing as the damages were premature and catastrophic in nature. Upon initial inspection at the dealer, they failed to identify the 2 holes in cylinder 6 piston. Suggesting that the "said holes" were nothing other than flaked carbon deposits. * There were no warning lights or any symptoms that would have indicated anything was wrong.

Filed May 28, 2026 · Engine · NY

Cylinder Misfires OBD-II code P0303 Engine Overheats after changed thermometer Fuel in the coolant system Coolant leaking from exhaust

Filed Apr 4, 2026 · Engine · MA

Check Engine light with Codes: PO300, and PO305. Misfire in Cylinder #5. Changed all spark plugs, and coils. Check engine still on, with same codes. Jeep dealer then said it was the cam shaft and needed new cam shaft head of a price tag of $8500. The car has been well maintained and has 75,200 miles on it. There is a known premature failure with the Pentastar Engine that is in this vehicle. Jeep is refusing to stand behind their product.

Filed Mar 16, 2026 · Engine · NJ

1. The issue involved the engine and emissions system, specifically a cylinder 3 misfire, accompanied by illumination of the check engine light and white smoke emitted from the exhaust. The vehicle was evaluated by an authorized Jeep dealership, which confirmed the cylinder misfire through diagnostic testing. At that time, per the diagnosis, coil 3 and all spark plugs were exchanged. This did not solve the issue. When picking up the car, check engine light was still illuminated and white smoke emitted from the exhaust. The affected components are in possession of the dealership, unsure if available upon request. 2. The engine misfire and associated white exhaust smoke created a risk of engine performance degradation, including potential loss of power, observed hesitation and stalling, which could impact the ability to safely operate the vehicle in traffic. Additionally, white smoke from the exhaust can impair visibility for surrounding drivers and may indicate an underlying engine condition that could worsen without warning, increasing the risk to the driver and others sharing the roadway. The chemical smell could also nauseate the person operating their vehicle, impeding their awareness and concentration. 3. This issue was proposed by an authorized Jeep dealership, then confirmed by two other mechanics. Dealer diagnostic records document the cylinder 3 misfire and investigation related to the check engine light and exhaust condition. 4. No inspection from manufacturer, police, or insurance representative. 5. Yes, the check engine light illuminated and the vehicle exhibited white smoke from the exhaust which prompted the service visit. Auto-start was not functioning as normal, with an error displayed on screen. Engine would sometimes stall upon start up during cold temperature days. NOTE: vehicle is currently with another mechanic awaiting an engine replacement, will upload that invoice once available.

Filed Feb 15, 2026 · Engine, Fuel system · OH

While driving this vehicle under normal conditions, the engine developed abnormal ticking/knocking noises, loss of power, and misfire symptoms that progressively worsened. The vehicle was frequently used to transport children. Due to the nature of the failure and unpredictability of progression, continued operation posed a serious safety risk. An authorized dealer later confirmed that the engine suffered a catastrophic internal valvetrain failure involving collapsed lifters/rocker arms and severely damaged camshafts. The dealer technician explicitly stated this failure mode is “typical” for this engine design and documented progressive internal damage affecting both cylinder banks, not an isolated component. This failure mode is not sudden; it develops gradually over tens of thousands of miles and can lead to sudden engine power loss, stalling, or seizure without warning. A loss of propulsion at highway speed, during lane changes, intersections, or while transporting children creates a clear risk of crash, injury, or worse. There was no evidence of driver abuse, lack of maintenance, lubrication failure, or misuse. The dealer confirmed oil condition and service history were appropriate. The defect appears to be internal, latent, and manufacturing-related, consistent with numerous consumer complaints, technical service bulletins, and ongoing litigation involving this engine family. Had the vehicle continued to be driven, the failure could have escalated to: •Sudden loss of engine power at speed •Inability to accelerate to avoid hazards •Engine seizure causing loss of steering assist •Increased crash risk with child passengers onboard The vehicle was removed from service due to safety concerns. This defect is repeatable, predictable, and well-documented, yet not subject to recall at this time. I am reporting this to support investigation into a systemic engine defect that presents a serious safety risk to drivers and passengers.

Filed Feb 1, 2026 · Engine · CA

Warped cylinder head without engine overheating. Cylinder 4 misfire.

Filed Aug 26, 2025 · Electrical, Engine · NY

CAM shaft and yes it is available to be looked at. The vehicle was misdiagnosed multiple times and sent back home with the same error code while fixing other items that were not the root cause of the issue. The engine light was on with the misfire code when I brought it in and was repeatedly sent home and within 20 miles the same code returned.

Filed Aug 16, 2025 · Engine · NY

The vehicle experienced a failure of the engine lifters/rocker arms, which also caused failure of the intake camshaft. This resulted in severe misfires, loss of power, and left the vehicle completely inoperable. The failure created a hazardous situation when the vehicle lost acceleration and was unable to maintain safe driving speeds, placing my safety and the safety of others at risk of collision. The problem was confirmed by Lou’s Car Care and multiple Stellantis dealerships, including Maguire Chrysler Dodge Jeep Ram. All inspections identified failed rocker arms/lifters and the intake camshaft as the cause of the malfunction. Critically, Stellantis no longer produces replacement intake camshafts for this engine, and the part is listed as indefinitely back ordered and unavailable. This means there is no factory fix, leaving the vehicle permanently disabled. Prior to the failure, the only symptom was a faint ticking noise from the engine. No warning lights or dashboard messages appeared before the incident. The problem escalated suddenly without adequate warning, causing the vehicle to lose power unexpectedly. This failure has caused severe negative consequences for me and my family. Because the vehicle became inoperable and the repair could not be completed, I lost my job due to lack of reliable transportation. I also experienced financial hardship, including losing my vehicle to repossession. My family, including my newborn child, was left without dependable transportation, which created additional safety concerns in emergencies. The failed components remain available for inspection upon request. This issue is widespread across Stellantis vehicles yet has not been addressed through a recall, despite the fact that the defect can cause sudden stalling or total engine failure at unsafe speeds. The unavailability of replacement camshafts means affected vehicles cannot be repaired at all, leaving owners stranded and financially devastated.

Filed Aug 14, 2025 · Engine · TX

Since the beginning of this year, vehicle began to misfire. So far I have spent over $2000 in repairs including replacing spark plugs, ignition coils, fuel injectors and oil cooler and vehicle continues to misfire and blow white smoke from exhaust. I have been advised that it may be a head gasket issue, which could cost anywhere from $3000 to $5000 but could cost more in the event the engine needs to be completely replaced.

Filed Jul 1, 2025 · Engine · IL

As many others have reported, only 56K miles on this 3.6L Grand Cherokee. When I engage the passing gear an auto stop/start light comes on on the dash followed by the check engine light. Vehicle rides very rough (from a misfire). Taken to an independent shop; they changed plugs and coils but the problem persists. Also a knocking / ticking noise can be heard when accelerating.

Filed Jun 20, 2025 · Electrical, Engine · CA

I was driving my 2018 Jeep Grand Cherokee Laredo 4x4 on the highway at approximately 65-70 MPH, when suddenly the car started sputtering and my check engine light came on and started blinking. The car was essentially not drivable, so I pulled over at a gas station and had the car towed. This is dangerous as I was going uphill, and could have caused an accident, or worse. I did not have a check engine light prior to this! The next day the car was inspected and diagnosed by independent service center, who said there was a cylinder 4 engine misfire, so they replaced the spark plugs and the coils. Car was fixed, or so I thought, fast forward a couple months later while driving to work, same issue (misfires and sputtering) occurs again and coolant now runs low even though there are no visible signs of coolant leakage. I spoke to the independent service center and they mentioned there might be an issue with the engine such as a head gasket or fuel system. I got the Jeep towed to get checked, it was confirmed that it was an engine issue, especially the head gasket, camshaft, pistons, and lifters, and that I was going to need a new engine and it would cost between $8500 - 13000. My Jeep has approximately 83K miles. The issues I describe here with this engine are all similar to those that have been reported.

Filed May 23, 2025 · Engine · NY

Head gasket/engine failure. Constant check engine light. First it was for a misfire and my engine was overheating. Had oil clogging the filter even though it was changed within the appropriate mileage. I got the check engine fixed April of 2024. May 20,2025, head gasket blew, causing me to now have to replace my engine completely. Same issues as previously reported