2018 Jeep Grand Cherokee: engine overheating

Filed Jul 22, 2026 · Engine · TX

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 the federal safety agency open a safety defect investigation into 3.6L Pentastar engine cooling failures and mandate a manufacturer recall with consumer repair reimbursement.

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 Feb 1, 2026 · Engine · CA

Warped cylinder head without engine overheating. Cylinder 4 misfire.

Filed Dec 3, 2025 · Engine · NC

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.

Filed Nov 3, 2025 · Engine · UT

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.

Filed Oct 27, 2025 · Engine · CA

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.

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

Filed Jan 2, 2025 · Engine, Transmission · PA

I'm writing to report a critical safety concern regarding the 2018 Jeep Grand Cherokee's water pump design. As an owner, I've experienced persistent coolant leaks, which I've found is a widespread issue affecting many others. This problem stems from a fundamental design flaw in the water pump, not typical wear and tear. The issue centers on a small "freeze plug" that leaks when the engine reaches operating temperature. This plug serves no apparent purpose and causes premature failures and coolant leaks across numerous vehicles. Key points: The leak occurs consistently when the engine is hot, indicating a design-related problem. This issue potentially leads to engine overheating and severe damage. It affects many vehicles, particularly those with the 3.6L V6 engine. Extensive research on online forums confirms this is a common problem. A YouTube video [XXX] ) provides insight into the issue. The creator states: "Upon digging into this a bit deeper, I don't believe it's the 'weep hole'. It's actually like a small 'freeze plug' that leaks on these pumps. If you look through the pulley at the opposite side of the aluminum freeze plug that leaks, you will see the weep hole. This 'freeze plug' that leaks serves no purpose as far as I see it. It's just like they slapped this plug in the front of the pump… and it leaks when it gets hot." Given this evidence of a design flaw and its widespread impact, I urge the federal safety agency to: Investigate the water pump design of the 2018 Jeep Grand Cherokee and similar models. Assess the safety implications, including the risk of engine overheating and potential vehicle failures. Consider whether a recall or other corrective action is necessary. The fact that this is a design issue rather than wear-and-tear underscores its urgency. All vehicles with this water pump design are potentially at risk, regardless of mileage or maintenance history. Thank you INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Nov 19, 2024 · Engine · OH

2018 Jeep Grand Cherokee Limited 3.6 L V6 Engines have a high rate of having HEAD GASKET problems around 100,000 miles causing vehicle to overheat and leak liquid into the cylinders damaging the engine. Please look into this problem at dealerships around the country with this year, make and model and discover how common of an issue this is with owners.

Filed Jul 20, 2024 · Engine · CA

Car dealer said that they already fixed the recalled issue. But we took car to the dealer also for car overheating in very short distances and the car only has about 67,300 miles. The dealer said that they "found stored DTC in PCM" P0304(Cylinder #4 Misfire). "There are combustion gases in cooling system." They said the car needed cylinder head replacement and engine replacement quoting me $8001.88 for repairs which I could not pay. The car has only been driven locally. We also suspect that this car may have been damaged by hurricane Michael in Florida in 2018 and damage may have not been reported. Car was bought in Florida in approx. September 2018 by owner 1 who sold the car to owner 2 with only approx. 2500mi after Hurricane Michael (Oct 9-10th). The car was sold to owner 2 in November 2018 in Florida then brought to California in 2021 and sold to owner 3 who is making this report. Or car may have already presented mechanical issues that may not been reported. Car has only been driven locally.

Filed Apr 20, 2024 · Engine, Fuel system · CA

Intermittent extended crank on cold starts and developed a misfire in cylinder 3 and the developed a misfire and coolant leak in cylinder 1. The dealer told me it needs a new engine due to internal engine failure. Codes p0303 and p0300. Engine only has 62,000 on it.