Spark Plugs The spark plugs insulator on approximately 48,000 of the above vehicles may break due to excessive cylinder pressure. This pressure can cause the spark plug's ceramic insulator to crack, leading to a rough running engine. If this issue is not resolved promptly, the broken fragments can fall into the cylinder and cause internal engine damage.
full bulletin at NHTSA ↗2026 Jeep Grand Cherokee engine problems
moderate Owners of the 2026 Jeep Grand Cherokee have filed 3 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of August 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
| Model year | engine complaints |
|---|---|
| 2022 Grand Cherokee | 19 |
| 2023 Grand Cherokee | 13 |
| 2024 Grand Cherokee | 27 |
| 2025 Grand Cherokee | 4 |
| 2026 Grand Cherokee (this page) | 3 |
Of the 22 model years of Jeep Grand Cherokee we track for engine problems, this one has the fewest owner complaints on file (3).
Owners are still filing on this — the most recent NHTSA engine complaint for this vehicle was logged 8 days ago.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
Engine Runs Rough Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Random/Multiple Cylinder Misfire Detected. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. Customers may also comment on the following: ● Engine runs rough. This bulletin involves replacing all four main chamber spark plugs.
full bulletin at NHTSA ↗SPARK PLUG - NONE
full bulletin at NHTSA ↗SPARK PLUG - NONE
full bulletin at NHTSA ↗MIL-On, Engine Runs Rough
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 3 most recent
This is for Jeep's brand new Hurricane 4 engine. The buyer has no option to chose the reliable 3.6L 6 cylinder in the 2026 Summit model. Theis 4 cylinders throttle response lag, from a stop or slow speed, is EXTREMELY dangerous! When trying to move into traffic from a street or driveway the Jeep just rolls slowly as if it was in Neutral; there is no acceleration. I can floor the accelerator…
The contact owns a 2026 Jeep Grand Cherokee. The contact stated that the check engine warning light illuminated and started blinking quickly before remaining continuously illuminated. The vehicle was jerking, and while it was in park, it vibrated excessively. The vehicle was taken to the local dealer; however, the cause of the failure could not be determined. STAR engineers later determined that…
I bought the vehicle less than 60 days when it had a major engine failure. The spark plug broke off into the engine and bounced around causing a failure. This is a known problem with this vehicle from the factory, from which I was not aware. At first they said they were putting a new engine in and now corporate is trying to get it out the door asap so they cant be forced to buy back the vehicle…
Common questions
How serious is the engine problem on the 2026 Jeep Grand Cherokee?
It's a documented issue but not catastrophic. 3 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.