2005 grand cherokee 4.7 rough idle in warm/hot weather.
i have a 2005 grand Cherokee jeep with a 4.7 v8 and 116k miles on it. bought it up in Alaska, currently live in south Dakota, and it hasn't seen any "hot" weather 75+ since Ive owned it...but 4 days ago, i drove down here to Oklahoma city, and on the way down i noticed on and off when i came to a stop it started shaking...then randomly stopped again. this has been going on all week now, but today(78F+), when i start it up, it runs smooth, then after a 5 to 10 seconds, it slowly goes into a shake. when it shakes it feels like a small 4 cylinder diesel.
I just changed all the spark plugs, didnt make a difference. And another thing, when it shakes, i can unplug each coil and on every one you do notice the RPM change and the shaking doesn't stop, so i dont think its a dead cylinder/plug/coil/injector. and even it would be a dead cylinder...it shakes a LOT worse then it would if I just had a coil misfiring.