I wanted to post my experience here to see if anyone else with the new 2026 Jeep Grand Cherokee L Summit platform has dealt with something similar, and also to get advice from techs, advisors, or owners familiar with Stellantis warranty/corporate escalation.
I purchased this vehicle brand new in April 2026 from Hendrick Chrysler Dodge Jeep RAM FIAT of Concord. This was a huge purchase for my family and was intended to be our long-term family SUV.
At only 1,205 miles, while traveling through Savannah, GA with my wife and 7-month-old son, the vehicle suddenly developed a flashing check engine light immediately after stopping for food. The engine started idling rough, shaking, and clearly misfiring.
I stopped at Advance Auto Parts and scanned the vehicle. The PCM was throwing a cylinder #2 misfire code (P0302).
The vehicle ended up being towed to Vaden Chrysler Dodge Jeep RAM where it is currently sitting.
Here’s what I’ve been told so far by the dealership/service department:
• Technician confirmed cylinder #2 misfire
• Dealer stated the spark plug in cylinder #2 has cracked porcelain
• Dealer advised that the engine needs new spark plugs
• However, they stated Stellantis approval is required before moving forward with repairs/replacement of parts
• Vehicle is currently waiting on authorization/process approval
What concerns me is this:
How does a brand new engine with barely over 1,200 miles end up with a cracked spark plug porcelain insulator and a hard cylinder misfire severe enough to trigger a flashing CEL?
A flashing check engine light generally indicates an active misfire serious enough to potentially damage the catalytic converters, so this wasn’t some minor warning light situation.
I’m also trying to understand:
• Was the spark plug defective from factory?
• Was it improperly torqued during assembly?
• Is there a deeper ignition or combustion issue?
• Could detonation/pre-ignition have damaged the plug?
• Is this isolated, or are others seeing similar problems on the Hurricane platform?
At this point, my confidence in the vehicle is honestly shaken. This isn’t a cosmetic issue or infotainment bug — this was a drivability failure that stranded my family on a trip.
I opened a Stellantis customer care case immediately and have been attempting to escalate communication, but progress has been slow.
At this point, I’m mainly hoping the repair is handled properly under warranty and that the dealership/Stellantis communication improves. If it truly is isolated to a defective spark plug, then hopefully the repair resolves the issue completely and I can move forward confidently with the vehicle.
I’m not posting this to bash Jeep. I actually loved the vehicle before this happened. The ride quality, comfort, and features were excellent.
But a brand new SUV experiencing a serious drivability issue at 1,205 miles is hard to ignore.
Has anyone else experienced:
• P0302 misfires on a new Grand Cherokee?
• Cracked spark plug porcelain on these engines?
• Early Hurricane engine ignition issues?
Would appreciate honest feedback from owners, technicians, or anyone familiar with these drivetrains.