Mgrantham
NAXJA Forum User
- Location
- Flagstaff, AZ
Hey guys. Having some trouble understanding what's going on with my jeep.
2001 XJ, 4.0, 4WD, 33" tires, about 7" of lift.
Today driving up from Phoenix to Flagstaff my check engine light came on. Pretty soon it started blinking at me. :shocked: The jeep is running fine, but I've never seen the blinking light before. I've read its the end of the world. I've heard its just showing an active misfire is happening. Got it coded at Autozone, it came back with 4 codes: P0300, P0303, P0304, P0305. I apparently have random misfires on cylinder 3, 4, and 5.
So here's the history. It has had random misfires before. Originally I believed it only happened at high RPMs and would reset the code. Sometimes it would come back quickly and other times it would come back a few months later. Recently it has been running slightly hotter than normal. A few weeks ago the radiator literally exploded. The theory is that there was a pinhole leak in the plastic railing that grew, dropped the pressure in the radiator, until the heat went catastrophic and exploded the side of an already defective radiator. Put a new radiator in, its been running just like before which was just slightly hotter than normal. Hotter than normal is just a tick above 210. Threw a new t-stat in and its running the same temp. Just slightly above normal.
So, assuming my cooling system is fine I have been hunting down the other reason my system has been running slightly hot. My thoughts are along the lines of faulty injectors making some cylinders run lean and causing heat up. Would this also cause my misfires?
I was supposed to drive this beast to Montana from Arizona tomorrow. So needless to say, I'm not going anywhere until I figure this out. The engine is running smoothly, even when the check engine light was blinking. I'm pretty stumped on this.
As a side note, I already have the foil under my injectors which I believe is the fix for heat soak and done by a previous owner.
So, any ideas?
2001 XJ, 4.0, 4WD, 33" tires, about 7" of lift.
Today driving up from Phoenix to Flagstaff my check engine light came on. Pretty soon it started blinking at me. :shocked: The jeep is running fine, but I've never seen the blinking light before. I've read its the end of the world. I've heard its just showing an active misfire is happening. Got it coded at Autozone, it came back with 4 codes: P0300, P0303, P0304, P0305. I apparently have random misfires on cylinder 3, 4, and 5.
So here's the history. It has had random misfires before. Originally I believed it only happened at high RPMs and would reset the code. Sometimes it would come back quickly and other times it would come back a few months later. Recently it has been running slightly hotter than normal. A few weeks ago the radiator literally exploded. The theory is that there was a pinhole leak in the plastic railing that grew, dropped the pressure in the radiator, until the heat went catastrophic and exploded the side of an already defective radiator. Put a new radiator in, its been running just like before which was just slightly hotter than normal. Hotter than normal is just a tick above 210. Threw a new t-stat in and its running the same temp. Just slightly above normal.
So, assuming my cooling system is fine I have been hunting down the other reason my system has been running slightly hot. My thoughts are along the lines of faulty injectors making some cylinders run lean and causing heat up. Would this also cause my misfires?
I was supposed to drive this beast to Montana from Arizona tomorrow. So needless to say, I'm not going anywhere until I figure this out. The engine is running smoothly, even when the check engine light was blinking. I'm pretty stumped on this.
As a side note, I already have the foil under my injectors which I believe is the fix for heat soak and done by a previous owner.
So, any ideas?