[Remmer6]

Hi everyone,
Looking for advice. Had an oil change and after that received Check Engine Light P0301(Cylinder 1 misfire). Took it to a mechanic and had Sparkplugs and Coils replaced.
Since then intermittently after driving for over an hr I have the check engine light come back on and between 70-80 MPH I will get engine surge for about 10-15mins. This then stops and I am fine for the rest of the trip. Took it back to mechanic and he could not find a problem. Took it to another mechanic who reported Spark plug had a hairline crack on Cylinder 1. Replaced it(again). I am still intermittently getting the Engine surge. Engine light does not always come on. Mechanic looked at it. Took it out for hr drive but could not reproduce the problem. He has hooked it up to the scanner and cannot find any fault.

Any ideas would be greatly appreciated. This is becoming very frustrating. Car runs great besides this intermittent problem. There is 155,000 Miles on it.

Rich

 

[Mark_]

Hi everyone,
Looking for advice. Had an oil change and after that received Check Engine Light P0301(Cylinder 1 misfire). Took it to a mechanic and had Sparkplugs and Coils replaced.
Since then intermittently after driving for over an hr I have the check engine light come back on and between 70-80 MPH I will get engine surge for about 10-15mins. This then stops and I am fine for the rest of the trip. Took it back to mechanic and he could not find a problem. Took it to another mechanic who reported Spark plug had a hairline crack on Cylinder 1. Replaced it(again). I am still intermittently getting the Engine surge. Engine light does not always come on. Mechanic looked at it. Took it out for hr drive but could not reproduce the problem. He has hooked it up to the scanner and cannot find any fault.

Any ideas would be greatly appreciated. This is becoming very frustrating. Car runs great besides this intermittent problem. There is 155,000 Miles on it.

Rich

Hey Rich, welcome to the forum And sorry to hear...

Just to get the ball rolling here : on that first oil change, did they do anything else, like replace the air filter ? Trying to figure out what happened, as this event seems to mark the beginning of your current problems... Maybe they accidentally disconnected a vacuum hose or something...

 

[Remmer6]

The only thing that stands out is they forgot to put the oil cap back on when returning it. I always double check amd pointed htis out to them.

 

[Gary Kline]

The only thing that stands out is they forgot to put the oil cap back on when returning it. I always double check amd pointed htis out to them.

Hey Rich,

Welcome from NY. Did the error ONLY start after the oil change? Also, is this the 4 or 6 cyl. Cherokee?

Lastly, can you describe what you mean 'engine surge'?

Best.

 

[Remmer6]

Actually after the oil change we instantly got a Check Engine light and p0301. Took it to our mechanic who said it wouldn't hurt to change the Spark Plugs and Coils. 6Cyl by the way.
The surging started after that(when I say surging, after driving on the Highway between 70 and 80 MPH it would feel like it was trying to pull forward every 2 seconds. No change in RPM just a little surge forward feeling. This would last 10-15mins and then the rets of the drive it was fine) I took it back to my mechanic who said he could find no fault. At this point I took the vehicle to another mechanic(recommendation from a friend). He hooked it up and said he was seeing Cylinder 1 misfire every 1000 revolutions. He said spark plug in Cylinder 1 had a small crack. He replaced it.
We drove it for several days. No Check Engine light and driving around town was fine. We had to drive into the city several days in a row(approx 2hrs each way) We had the surging issue happen twice(again it's very intermittent). No check engine light. Took it back to the mechanic who drove it for an hr on the highway and he could not reproduce the problem. Driving again last night same issue. This is our main commuter car as our other one is a Wrangler lift and 35" tires and we get like 13mpg. lol. Just getting frustrated with this issue.

Much appreciated everyone.

 

[Gary Kline]

So current status is no light but 'surge'?

Do you have AlfaOBD or a similar tool that could tell if there are codes present (that may not necessarily be triggering the CEL)

 

[XJ99]

Does this "surge" feel like the Jeep has the hiccups?

 

[Remmer6]

I do have a OBDII scanner. Only code was P0301. Hiccups is the perfect way to describe it.

 

[Gary Kline]

I do have a OBDII scanner. Only code was P0301. Hiccups is the perfect way to describe it.

The cyl 1 misfilre code. Does your tool have the ability to show how many misfires are reported once you reset it? (how frequent is it happening)

• 1. Do you hear any clicking coming from your engine (Check YouTube: "Pentastar Tick")

It's also possible that the P0301 had nothing really to do with the oil change (other than timing) and it's a bad rocker in cyl 1.