Bought my truck about 2 years ago with a "misfire" (at least thats what the dealership told me)... Replaced all the coils and plugs, yet still ran like crap. I figured since it didn't seem too bad at the time, I decided to leave it alone until it got a little worse so that I am not just throwing money into it and not fixing the problem. Well recently I have noticed it got a piss load worse... I put my elbow on my center console at a stop light and my hand shakes involuntarily like I am having a freakin seizure... Literally the entire truck shakes. Thankfully the shop I work at has many knowledgable mechanics, one of which came up with a very possible/understandable explanation. He believes that the timing might be off on one of the chains. One of the codes says that bank 2 is running rich. When doing a relative compression test, cylinders 5, 7, and 8 all have slightly low compression and guess which bank those three are on... bank 2... Strangely cylinder 6 is fine, but I still need to do a manual compression test and/or vaccuum test. Gas mileage is horrible (I average 10-11 city) which I can understand if the timing is off and the valves aren't opening and closing at the right times, wasting gas like crazy. The cats are fine and after doing a fuel pressure test, can see that all of the injectors are fine. Any other ideas as to what might be causing this?
My truck would idle real rough, had worse mpg's then you're getting and had a lean code. It ended up being an o2 sensor. Not sure if a sensor could read as running rich; But it is an option. She seemed to run alot better too after the o2 was replaced.
I will definitely look into it and ask the guys at work what they think, that would be a muchh simpler fix... Thanks for the input man
This ended up being the fan clutch. I knew it needed to be replaced cause it actually was stuck engaged (thankfully not the other way around) so I could still drive it without over heating, but I finally bit the bullet and went with the cheaper option of replacing the fan clutch instead of both O2 sensor and my truck has never ran smoother!
Glad to hear to hear you figured it dude. I never would have guess it would have been the fan clutch though.
Same here! Heck that's why I never even thought to check it, but after thinking about it it made sense, if it is constantly engaged, and a few of the balls from the bearing are missing making it spin crooked, that much momentum up front could easily cause a crazy shake throughout the truck. Didn't know it'd be that bad though :/