Re: '04 WJ, bizarre misfire of sorts
Well, after a very long stint of being quite sick, I finally got the opportunity to change out my O2 sensors. No notable difference. It was warmer (in the 60's) earlier in the week and again, it ran much quieter and smoother. Now it's cold and the Jeep's loud. There's always been a slight bit of stumble to it sitting at a light. Is it possible that what I'm hearing is the broken exhaust manifold bolt issue I've been hearing about?
My thought (and please feel free to tell me if I'm smoking something here) is that maybe the manifold starts off relaxed and pressed up tight to the head. Then after a few minutes of running it heats up (unevenly) and warps and pulls away, creating an exhaust leak on one cylinder. The colder it is, the worse the warpage until everything stabilizes in temperature and sort of un-warps to a point. After running it for better than 20 minutes it quiets down some and runs a bit better. If I shut it off to run into a store or something, it will typically be better after sitting for 10 or 12 minutes.
Yesterday I noticed that the problem started just prior to it going into closed loop mode, as when I got on the freeway it was not warm enough yet to engage overdrive. It allowed OD about 3 or 4 minutes after it started running obnoxious. Is that theory at all feasible or am I going the wrong direction?