2020 Jeep Grand Cherokee: misfire or rough idle

Filed Mar 7, 2026 · Electrical, Engine · PA

on or around 12/15/2024 (42257 miles on vehicle) jeep will power on start and stop, all alights on dashboard light, unable to shift into or out of gear when parked. When driving but stopped at a red light car shut off. Attempted to restart unable to, car put into park attempted to restart lights came on but engine didn't turn over. Tried again few minutes laster and the car turned on. Returned apartment, parked car. was unable to shift car into park, car shut off on its own again, car then able to go into park. A few days later start engine, car turns on put car in reverse, car shut off on its own, all lights and warnings on dashboard light up and stay on. Unable to start engine, unable to shift car into park. turn car off, shift into park, on 12/17/24 Car towed to Lake Chrysler dodge jeep ram auto Lewistown PA. told that it was the can bus connector needed to be replaced. Part replaced. 10/10/25 (54630 miles) car in for inspection, oil change, reported to mechanic engine was making high pitched sound/noise when driving up steep hill on highway the week prior. Was told by mechanic "that is normal when driving up steep hills, after a long drive" " we didn't hear it or find anything" Car continued to make this noise on the same hill since. Car in for oil change at David Dodge on 1/12/26 (58,974 miles) reported to mechanic again that engine continues to make a high pitched sound/noise when going up hills, on highway drives and after longer drives. per shop nothing was found. Asked if I should make an appointment for it to be tested and told no not needed. On 3/2/26 check engine light on, waring start/stop unavailable service stop/start system this happened off and on for next few days. Car brought to mechanic on 3/6/26 (60,000 miles) diagnosic test run cylinder misfire, R and R intake manifold to check coil and spark coolant found on spark plug, borescope #3 cylinder Head gasket, cylinder head, block issue . Recommend total engine and radiator replacements

Filed Jan 8, 2026 · Engine · NY

This complaint concerns a serious ongoing engine defect in my 2020 Jeep Grand Cherokee Limited with the 3.6L Pentastar engine. The vehicle experiences ongoing misfire, rough idle, loss of smooth engine operation, and valvetrain noise. The Jeep runs very poorly and feels unreliable and unsafe to drive. The problem appears to be consistent with camshaft and rocker wear described in Stellantis Technical Service Bulletin 09-011-25. The vehicle has been repaired three times at: NJV Auto Center Inc. 27 Orange Turnpike Sloatsburg, NY 10974 Despite being $2,500 out of pocket, the issue has NOT been resolved. This appears to be a widespread manufacturer defect affecting Pentastar engines. Loss of proper engine function while driving is a safety concern and creates risk of breakdown or loss of power. I am requesting the federal safety agency investigate.

Filed Sep 15, 2025 · Engine · NJ

P0303 code. Misfire in cylinder 3. Blown head gasket. 2020 Jeep Grand Cherokee. Car is only five years old with 115000 miles. Dealer suggested a new engine. A $12,000.00 expense to the consumer. $20,000.00 still owed to bank. After much research, it’s clear as day that this is an engineering flaw. Thousands of Pentastar engines have this recurring failure.

Filed Jun 16, 2025 · Engine · GA

[XXX] Utility 4D Altitude 4WD 3.6L V6 2020 Jeep Grand Cherokee My 2020 Jeep Grand Cherokee with 3.6L Pentastar V6 engine check engine light came on at 115,000 miles with a P0305 code. The P0305 code for a 3.6L Pentastar V6 engine indicates a misfire in cylinder number five. The week prior I performed a coolant flush and fill with the proper Mopar coolant. A few days later the water pump weep hole started leaking. I replaced the water pump and changed the spark plugs. A few days after this was when the P0305 check engine light came on and I could feel the engine starting to stumble from the misfire. No indication of overheating, coolant temperature was normal between 180 F and 210 F. I kept checking the coolant level and noticed the level dropping after a few days. There was no indication of a coolant leak after replacing the water pump. No coolant in the oil, or oil in the coolant and no white cloud from the exhaust from the coolant leaking into the combustion chamber, typically caused by a blown head gasket, cracked head or block or warped head or block. I set an appointment at the Jeep service department, and they informed me the engine had to be replaced. They said they did a bore scope test and a leak down test to confirmed the coolant was leaking into the cylinder. There are hundreds if not thousands of reports from other owners of Jeep Grand Cherokee and other Jeep, Chrysler, Ram, Dodge owners reporting this same issue. The attached photos show no coolant mixing with the or oil mixing with the coolant, resulting in the coolant only leaking through the combustion chamber to the exhaust confirming the service departments findings. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 14, 2025 · Engine · 61,000 miles · MI

The contact owns a 2020 Jeep Grand Cherokee. The contact stated while driving at undisclosed speeds, there was a misfire coming from the engine while accelerating, decelerating, idling, and while parked. The check engine warning light was intermittently illuminated. The vehicle was taken to the dealer, who diagnosed that the right-side intake camshaft on all 6 lobes had ground away and needed to be replaced. Additionally, metal was found in the rod bearings in the engine. The vehicle was repaired. The manufacturer was made aware of the failure and opened a case. The manufacturer referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 61,000.

Filed May 11, 2025 · Electrical, Engine · CA

Took to dodge dealer and they told me they have been have problems with traction control, 4x4 problems, misfiring cylinders . They spent 5 days trying to figure it out and told me it was a process of elimination . Replace rear diff motor and that didn't work, replaced TCCM, that didn't work, replaced both batteries , that didn't work, new spark plugs, that didn't work, replaced coils on the side where #1 cylinder miss fire, that didn't work. I've spent approximately $6,000 and still have same problem. I do not have unlimited funds. What should I do next?

Filed Apr 28, 2025 · Engine · CO

While I was attempting to pass a vehicle on a two-lane highway, my engine started misfiring and I lost engine power and it almost caused a head-on accident. The engine had to be replaced because the camshaft was worn on bank 1 and after doing some research there seems to be a lot of issues with this engine and the rocker arms which wears the camshaft down. There was a lot of metal in my engine which caused them to have to replace it. I researched recalls and there is nothing but after speaking with the dealership they confirmed that there is a known issue with this engine.