Cylinder 1 Misfire
Asked by Justine Feb 03, 2020 at 09:32 AM about the 2015 Jeep Grand Cherokee SRT 4WD
Question type: Maintenance & Repair
2015 SRT Grand Cherokee, 84k miles, original plugs and coil packs.. did a little
launch in the car, got a check engine light P0301 - Cylinder 1 misfire. Could it
be plugs and packs?
7 Answers
It's easy to eliminate a plug or coil pack as the cause, just swap it around with one of the others, and see if the problem follows. You could also have a bad injector. (You don't have to swap around an injector, you can unplug it while engine is running and listen for a change in idle.) When you do swap any of these around clear the code and wait to see if it comes back. Most better quality code scanners can clear a code. A code will clear itself but it may take a while. After all this, you start to get into mechanical reasons for a misfire, namely a bent valve, bad lifter, timing, or head gasket. A bad EGR can sometimes show up as a cylinder 1 misfire. But unless you've really been beating on your engine, those aren't typical at only 84K miles.
I would go ahead and change the plugs as you are near the time to do so anyway.
Book states plugs should be changed at 100k. My stop/start option had stopped working days ago. I had a week-end excursion planned for months. Driving down the highway, my "A!" light came on as the car bucked lightly. I thought it was the road until I noticed the light. Accelerating, the check engine light began to blink, eventually becoming constant as the vehicle began to shake. I had the code checked. I called my dealership to make an appointment for the next business day. I related the code and told them that , at the very least, i wanted my spark plugs replaced. I dropped it and it was diagnosed as my needing spark plugs as 3-4 of my plugs were misfiring(Duh-I told them that). That was $554.57-2 days ago. This morning the same stop/start "A!" light came on, the vehicle is bucking lightly and the check engine light blinking. The plugs might not necessarily be the actual problem, but a symptom.
Hey guys, was this problem ever resolved? I am having what seems like the exact same problem. I've already replaced all of my spark plugs & the EGR valve as those were the codes my scanner was throwing at me. I've got a 2016 Overland Grand Cherokee with about 100k miles on it. Thanks in advance!
Guru9FFGJC answered about a year ago
Anyone else figure out the issue with the stop/start light coming on and engine light following acceleration?
Hey guys. so I had the car looked at and they had to replace the cam and there was an issue with the ECU they claimed. I think they lied about the ECU because it was tuned and the time was still on the car. But they replaced the cam and lifters.
Guru9FFGJC answered about a year ago
After replacing cam and lifters issue was resolved? The dealership has no idea so far after a full day of diagnosing. Once I step on the gas hard the stop/start light comes on and then the engine light is lit permanently.