New Jeep, "The Heep"
09-25-2017, 12:13 AM
#1
Newbie
Thread Starter
New Jeep, "The Heep"
Hey guys, long time lingerer finally made an account. I'm moved to Washington with the Army recently and decided to buy a jeep while I was here. Its a 2001 XJ with 220k on the dash. Last guy did some work on it and obviously had no idea what he was doing. Fixed all the "major" problems and a lot of small/cosmetic ones but theres one I can't get.
I did search and found the numerous misfire threads, but one miss is not the same as the next from what I've seen and I'd like some first hand opinions.
When I first got it there was a miss on cylinder #4. Changed the spark plugs (a miracle the thing was running at all with the state of them) and now the miss moved to cylinder #6. Its to the point that the CEL blinks while driving and I get "chugging" when accelerating. I noticed when I replaced the valve cover gasket that one of its bolts had been broken off in the head (I suspect over torque) by the previous owner. The valves looked fine, and I put everything back together and left the broken bolt as is.
I replaced the coil pack next, slight improvement but still a miss. Swapped around the fuel injectors, miss didn't follow the injector. Good fuel pressure.
Decided to inspect the plug on cylinder six for the heck of it and it was black with soot and smelled like burnt plastic.
Right now my two suspicions are the head is cracked from that bolt next to the fire wall being over tightened, or maybe the exhaust manifold/gasket that I installed wasn't seated properly or something.
I did search and found the numerous misfire threads, but one miss is not the same as the next from what I've seen and I'd like some first hand opinions.
When I first got it there was a miss on cylinder #4. Changed the spark plugs (a miracle the thing was running at all with the state of them) and now the miss moved to cylinder #6. Its to the point that the CEL blinks while driving and I get "chugging" when accelerating. I noticed when I replaced the valve cover gasket that one of its bolts had been broken off in the head (I suspect over torque) by the previous owner. The valves looked fine, and I put everything back together and left the broken bolt as is.
I replaced the coil pack next, slight improvement but still a miss. Swapped around the fuel injectors, miss didn't follow the injector. Good fuel pressure.
Decided to inspect the plug on cylinder six for the heck of it and it was black with soot and smelled like burnt plastic.
Right now my two suspicions are the head is cracked from that bolt next to the fire wall being over tightened, or maybe the exhaust manifold/gasket that I installed wasn't seated properly or something.
Last edited by Matthew Price; 09-25-2017 at 12:18 AM.
09-25-2017, 10:59 AM
#2
Junior Member
First thing is to find out what trouble code(s) your jeep has. Could be more than a few things that cause that issue. If you have an android smart phone I suggest downloading the TorquePro app and getting a bluetooth OBDII dongle. Will be able to read codes and see sensors in real time. A bad O2 sensor can cause fueling issues along with vacuum leaks or exhaust leaks.
09-25-2017, 11:09 AM
#3
Newbie
Thread Starter
Only code I’m getting on my cheapo reader is P0306 cylinder 6 misfire detected. I did just replace the bank one sensor 2 O2 sensor a few days ago when I did the coil pack.
09-25-2017, 01:05 PM
#4
Junior Member
Good copy. Hopefully someone comes along who has done the troubleshooting on this to help you out. A vacuum test and a compression test would help to confirm or deny the 2 issues you bring up, especially with 220K on the clock.