Plumes of smoke after extended idle at traffic lights and traffic jams? Does the smoke stink of burnt oil? If so, then that's a classic symptom of valve stem seals leaking. My '05 4.4 has the exact symptoms and I'm not going to spend more than 50% value of the vehicle to have it fixed. I heard in this forum about a "temporary fix" and implemented it- shell rotella t6 5w40+2 quarts lucas engine oil stop leaks + 8 oz atp205 seals rejuventor. Not a puff of smoke and I'll fix it myself when I get time and correct tools. In the meantime, I'm enjoying my ride and no embarrassing plumes of smoke
. I have not noticed any detrimental side effects to engine performance thus far (12k miles). Last oil change looked good. After all, these engines are not made of gold, diamonds and silver so I'm not worried.