2018 Jeep Grand Cherokee engine problems

ENGINE AND ENGINE COOLING

The contact owns a 2018 Jeep Grand Cherokee. The contact stated that since the vehicle was purchased, there was an abnormally strong coolant odor coming from the vehicle. The dealer was notified of the failure and informed the contact that the coolant reservoir was recently refilled, and the odor might be due to an overflow. The contact stated that the failure persisted, and the vehicle was taken to the dealer, where the water pump was replaced. The contact stated that the water pump had been replaced approximately nine times under warranty due to the strong coolant odor and a water pump leak; however, the failure persisted. The vehicle was not yet repaired. The manufacturer was notified of the failure, and a case was filed. The failure mileage was approximately 125,000.

NHTSA complaint #11757611 — an unverified report by a vehicle owner.

ENGINE

Vehicle Information: 2018 Jeep Grand Cherokee Overland 3.0L V6 EcoDiesel 4x4Component Affected: Fuel/Propulsion System (High-Pressure Fuel Pump) Safety Incident Narrative: The vehicle previously underwent a mandatory manufacturer safety recall replacement for the Bosch CP4 High-Pressure Fuel Pump under FCA Safety Recall Z46 (NHTSA Campaign Number: 22V-406). At 111,948 miles, while operating the vehicle, the engine suffered a sudden, catastrophic mechanical failure accompanied by an immediate and total loss of engine oil pressure. This caused the engine to suddenly stall and lose all propulsion while in motion, creating an immediate and severe highway safety hazard to myself and surrounding traffic.The vehicle was towed to an authorized Jeep dealership under Repair Order #5823328. The manufacturer (Stellantis) and the dealership are currently refusing to authorize diagnostic teardown labor or a mechanical review of the internal safety recall componentry to investigate an acute internal fuel-pump shaft seal leak or residual micro-particle metallic debris from the prior campaign. An internal drive-shaft seal failure on this replacement pump architecture dumps raw diesel fuel directly into the engine's internal oil crankcase, causing severe oil dilution, an immediate collapse of structural oil pressure, and catastrophic engine seizure. The manufacturer is attempting to shift 100% of the financial burden ($25,000 engine replacement cost) onto the consumer, actively obstructing an essential safety failure investigation into a federally recalled component.

NHTSA complaint #11756569 — an unverified report by a vehicle owner.

ENGINE

VEHICLE & PURCHASE DETAILS: 2018 Jeep Grand Cherokee (3.6L V6 Pentastar Engine). Purchased on/around April 27 in agreement with my credit union. INCIDENT & DEFECT DESCRIPTION: Upon taking delivery, the vehicle immediately displayed diagnostic warning codes. The selling dealer attempted diagnosis/repair for a week before directing me to take it to Bonham CDJR in Bonham, TX. Bonham CDJR cleared the codes and returned the vehicle. A couple of weeks later, while my wife was driving home, the engine suddenly and severely overheated without warning. I instructed her to pull over immediately to prevent engine destruction or stall in active traffic. My wife was stranded on the roadside in extreme Texas heat until a flatbed wrecker towed the vehicle back to Bonham CDJR. WARRANTY OBSTRUCTION & KNOWN FAILURE POINT: Upon arrival at Bonham CDJR, I informed service advisors that my third-party warranty provider (First Guard) would handle coverage. However, the dealership demanded a $1,300 upfront, out-of-pocket engine teardown fee just to "prove" the cause of failure to the warranty company. The 3.6L V6 Pentastar platform is notorious for cracking plastic oil filter/cooler housing units and failing thermostat assemblies, causing rapid coolant loss and overheating. Requiring consumers to pay massive teardown fees out-of-pocket to diagnose a known, unaddressed manufacturer design flaw creates an administrative barrier that leaves defective, dangerous vehicles on the road. SAFETY HAZARD & IMPACT: Sudden engine overheating at driving speeds causes sudden power loss, severe traffic hazards, thermal fire risks, and roadside stranding in hazardous ambient heat. This ongoing ordeal has caused severe personal distress, financial strain, and loss of wages. REQUESTED ACTION: I request NHTSA open a safety defect investigation into 3.6L Pentastar engine cooling failures and mandate a manufacturer recall with consumer repair reimbursement.

NHTSA complaint #11752136 — an unverified report by a vehicle owner.

ENGINE

* 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.

NHTSA complaint #11744663 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

See attached document for complaint.

NHTSA complaint #11743276 — an unverified report by a vehicle owner.

ENGINE

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

NHTSA complaint #11740706 — an unverified report by a vehicle owner.

ENGINE

On 5/72026@app 3:14pm after picking up one grandchild, and at a stop light on the way to p/u the other, the Jeep without warning just disengaged when the gas pedal was depressed, but to no avail. While frozen, the dashboard may have displayed something that was not noted in the panic to get the car moving! The internal panel was still illuminated, however the car would not move forwards although still in "Drive" with nothing having been switched, shifted or toggled except engagement of the brake to stop at the traffic light. The Jeep had to be placed in "Park", the starter button pressed, then pressed again to completely restart the vehicle. This was a potentially huge safety issue with many cars around us honking & rushing to pick up their own children, yet fortunately no one ran into us with our precious little rider!

NHTSA complaint #11737894 — an unverified report by a vehicle owner.

ENGINE

There are parts in the engine that malfunctioned and have caused fluids to leak into the engine. This is causing the engine to fail and requiring replacement. This issue started last year for me personally. The car has been to 2 mechanics and they both have diagnosed the issue , and to fix it requires full engine replacement . It’s a safety issue because the engine can lock up and stop the car.

NHTSA complaint #11736347 — an unverified report by a vehicle owner.

ENGINE

I recently purchased a 2018 Jeep Grand Cherokee and began experiencing serious issues almost immediately after taking possession of the vehicle. The vehicle has stalled unexpectedly while driving on multiple occasions, including during active driving conditions. It also has difficulty starting and has shut off without warning. The vehicle has already undergone multiple repairs within a short period of time, including work related to the radiator, spark plugs, and ignition coil. Despite these repairs, the issues continue. This creates a significant safety concern, as the vehicle becomes inoperable without warning, especially during daily highway driving. I rely on this vehicle for transportation, and it is currently unreliable and unsafe to operate.

NHTSA complaint #11735876 — an unverified report by a vehicle owner.

ENGINE

had a recall done in February and 3 weeks later the car would not start randomly no warning lights illuminated on the dash prior to being shut off and once it would start it threw 3 codes for p0850, u0100, and U1267 all related to the parts replaced in February for the recall for the 2nd time now regarding the same parts. and trying to get a reinspection done for the recall bc the parts seem to have failed and its been a living nightmare. and unsure why no warning lights were illuminated prior to the car not starting randomly

NHTSA complaint #11733528 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11729198 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11724620 — an unverified report by a vehicle owner.

ENGINE

Had the ABS Module repaired due to recall last week. Next, I have had 3 instances of the Accelerator sticking when shifting gears and, this never happened before this service.

NHTSA complaint #11721439 — an unverified report by a vehicle owner.

ENGINE

Issue with camshaft. Dealership said there has been an influx of vehicles with the same engine and the same issues.

NHTSA complaint #11718926 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11718096 — an unverified report by a vehicle owner.

ENGINE

Warped cylinder head without engine overheating. Cylinder 4 misfire.

NHTSA complaint #11714823 — an unverified report by a vehicle owner.

ENGINE

The check engine light keeps coming on. The Jeep repair shop says that it has to do with the flap on the gas tank where you put the gas in. Hence, the repair light keeps coming on so you never know if its real and needs to be addressed or if its the gas tank issue again

NHTSA complaint #11711912 — an unverified report by a vehicle owner.

ENGINE

I purchased my Jeep in 2023 and have consistently stayed up to date on all required maintenance. I had no issues with the vehicle until recently, when the check engine light and the start/stop warning appeared out of nowhere. After inspection, the mechanic determined that the entire engine needs to be replaced due to severe coolant leakage. My vehicle has now been in the repair shop for over three months because the engine is on national backorder. I contacted the dealership, but they dismissed my concerns and told me that once the car is purchased, it’s no longer their responsibility. I then reached out to the manufacturer requesting a goodwill resolution, given the unreasonable repair delay and the national backorder of such a critical component. Lemon law mileage limits do not apply to goodwill assistance, trade-in support, or corporate escalations. Despite this, the manufacturer has refused to provide any explanation or documentation for why they cannot assist and it has been three months with no progress. There were no warnings or indicators that something was failing internally, and my mechanic confirmed there was absolutely nothing I could have done to prevent this. I’ve also seen numerous reports of this same issue affecting my specific make and model. Stellantis needs to take accountability. It is completely unfair that I am left without reliable transportation for months over an issue that was entirely out of my control.

NHTSA complaint #11702850 — an unverified report by a vehicle owner.

ENGINE

In September 2025, the vehicle was shaking upon idle when we started it. We did a test and learned it was somehow losing coolant. We took it to a mechanic who discovered it was burning coolant in the 5th cylinder. They diagnosed the issue as blown head gaskets caused by the engine being machined incorrectly by the manufacturer. This resulted in the need for a short block removal and replacement, resurfacing the cylinder heads, replacing the head gaskets, among with many smaller repairs. The cost was over $8,000 total for a manufacturing error. If left unresolved, this could have caused further mechanical issues and potentially a crash or other safety issues.

NHTSA complaint #11697308 — an unverified report by a vehicle owner.

ENGINE

My 2018 Jeep Grand Cherokee suffered a sudden, catastrophic engine failure with no warning lights or alerts. Dealer confirmed the engine seized from overheating and cannot be repaired—replacement engines are on national backorder. This is my only vehicle, I’m 7 months pregnant, and I’ve been without transportation for 30+ days. This appears to be a widespread 3.6L Pentastar defect and a serious safety concern.

NHTSA complaint #11695830 — an unverified report by a vehicle owner.

ENGINE

Water pump failure.

NHTSA complaint #11691390 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11683140 — an unverified report by a vehicle owner.

ENGINE

TURBO supply line broke causing coolant to go all over the engine.

NHTSA complaint #11681609 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11681112 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11680540 — an unverified report by a vehicle owner.

ENGINE

Rockers & cam shaft are worn and making ticking noise. I only have 86k on my 2018 Jeep Grand Cherokee, and am diligent with upkeep on the maintenance. This is a very known issue and should be recalled as I have not driven it anymore to prevent further damage to the engine, and also don't have the funds to fork out almost 5k.

NHTSA complaint #11677687 — an unverified report by a vehicle owner.

ENGINE

I have been without a vehicle for over 5 months. Paying on a vehicle that I cannot even get out of the garage. Paying storage insurance on a vehicle. There is a major issue with camshafts right now. I have had the spark plugs changed, coils, oil and I was waiting on the camshaft which is on back order for who knows how long. This needs to be addressed and recalled. With the amount being over 14,000 parts on back order I think this should be recalled. Even people who have had the camshaft fixed are still having engine issues with the 3.6L. Please do something about this, I have put so much money into this and I need a vehicle. At 75,000 miles this should not be happening.

NHTSA complaint #11676177 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11670468 — an unverified report by a vehicle owner.