Ground Straps on 03 4.7 HO on Coils
So this is a odd issue, that I have been chasing for about 3 weeks now. I have access to a Genisys scan tool that a friend of mine has and I wanted to just check out to see how everything is running with a live data stream. Ok So I noticed that i had a Very slight misfire on cylinder #8 it was not enough I guess to throw a p0308 code. I just found it odd that I had this issue. So with it being an 03 with 65,500 miles on it and it was well maintained before and I still do the same just changed all fluids within the past 6 months, oil changed on a regular basis. Anyways I had not changed the spark plugs. So I figured ok it's time found the champion version of the mopar plugs (wjjeeps.com) platinum, gapped to spec (0.040). Pulled out all of the plugs and coils the plugs were dry, just a little tan in color no real bad carbon marks looked pretty good. #8 was a little oxidized that was it, One thing I noticed on the removal procedure from alldata and wjjeeps.com that I needed to make sure that the ground straps were reattached to cylinders #4,#8. Now when I took off the mounting nut on these coils there was not a ground strap.
Ok So I say hey maybe this is why I was getting such an odd misfire on #8 that is so faint the coils were not grounded correctly. Now when I took everything off the boots looked brand new no rips tears nothing. Looked new. I even took took it to my dealer to have them measure it as I am good friends with the service director and he's like your messing with me you just bought this... and he then noticed I wasn't driving my car.. So he said measure the resistance make sure the spring was good inside, spring was good the ohms were within spec. ( I forget off the top of my head what it should be)
Ok that is all of the background, what really got me to this was I heard a tick/knock in the engine... seafoam didn't work. Bought a can of Mopar Combustion chamber cleaner. OMG Did the smoke show come.... that was the first time with 1 can. then ran chevron techron fuel cleaner thru 3 tanks of gas, then changed the plugs... Well I attached the ground straps since they were just hanging there. made sure it was a good ground with my DVOM. all was well started up and MY MY what a difference. Ran smooth, quiet, slight tick. Typical with any chrysler 2.7,3.7,4.7,5.7 engine.. WELL I got the scan tool up to it after a week of driving. Had no codes just wanted to check for the slight misfire on #8 well #4, #7 #8 #1 all had them but again didn't throw a code. So today I put 2 cans of MCCC thru the throttle body and WOW even MORE SMOKE I mean I had to leave my neighborhood cause I heard sirens coming and MAN did it stink. Let it sit for 3 hours after I had put 2 cans thru it.. Well rescan p0300 p0304 p0307 p0308.... WTF!!! cleared them drove it.. gone... I was talking with one of the techs at my dealer that helps me now and again he said sometimes 3-5 times of doing it will really get it done and cleaned out. AS the Jeep sits now even before this I have a slight skip in the idle. And before the treatments I was at 780 RPM idle and plug change now I am at 640 where I am supposed to be but when it "skips" it's dropping from 640-608 so that's what had me do the treatment again. Oil is still clean. not black running full synthetic 10w-30 pennzoil Ultra.
So I turn the key to the on position and the engine light flashes 12 times. I noticed that all but 3 of my I/M monitors are working. Ok I noticed I need to do a few drive cycles since I reset codes to get them all to come back on and I need an inspection sticker so I need the to the exact I believe it's a 6min and 45 sec trip I have it written down.. Anyways... I know this is alot of info But could have the ground straps been removed previously because of this? I did check the ground throughly today and it is good. ALSO I noticed when I ordered my build sheet from Chrysler I had an engine block heater. I never knew... WEll I found the plug... and the ground straps go over that plug but do not touch. I have not even tried plugging it in.... First off It's not that cold in mass right now.. second I am not sure it works.. and don't want that to cause an issue.. I may be able to "borrow" a wITech scanner from the dealer and just use it in the parking lot. But regardless has anyone ever any symptoms like this? Anyone got any ideas?? The skipping and the smooth idle are starting to get better. the skip is less and the idle is smoother, I know there is a TSB in regards to a warm rough idle and that the PCM needs to be re flashed... Through a VIP inquiry I had my buddy at the dealer do it has not been done. Could it be that simple?
I know I am going on and on. But I am just trying to make this run as best as I can gas is not cheap!!
Any help and ideas would be very much appreciated!!