I have a 2004 Isuzu Axiom that has a check engine light on. The engine is bogging down and burning a lot of oil and is reading a misfire on the number 4 cylinder when i hooked up the diagnostic tester to the OBD II. The positive crank case ventilator was clogged with oil, it helped cleaning the pcv but continued to burn oil and read a misfire on valve 4. When doing a compression test all cylinders are reading 95. To test the coil packs we looked at the resistance on the main coil between the plug and power and all had similar resistance on them, the spark plugs had some residue on them but were still getting a spark. When we ran the engine and unplugged each pack the engine slowed with each cylinder was taken offline leading me to assume all the coil packs are doing something. When we were inspecting the inside of the manifold and cylinders with a boroscope they seemed to have some exess oil residue but otherwise nothing to note. I will be doing another compression test and a leak down test on it, would anybody have any suggestions how to trouble shoot the problem. I am guessing it is some misfire caused by something mechanical but I would not know how to determine what those could be. Most troubleshooting focuses on fuel and ignition but the bogged down engine coupled with the burning oil is difficult to single out.
Any insight would be greatly appreciated.

 

I picked up a new compression tester and the compression of all the cylinders were between 190-200. I also did a leak down test and there wasn't a noticeable difference between the cylinders (there was barely any air escaping through the manifold.

 

just FYI, my 04 axiom has always used at least a quart of oil between changes, now at over 140K miles it uses more than a quart. No leaks, so it must be burning it, but no signs of smoke either. Engine runs great, always has, no major work other than typical tune-up and timing belt replacement. But the use of oil has always been a concern, but nothing has come of it as yet. Still driving the 04 axiom, really like the reliability and ride and features on the vehicle after over 10 years of owning it.