I have a 2007 dodge ram 1500 4.7L V8 FFV. 136k miles. Oil changes every 3k, spark plugs were done at 135k. New air filter, new PCV valve, throttle body cleaned at 135k also. So i've been noticing my truck running rough so I check the oil and it's 4 quarts low, had just done an oil change 1500 miles prior. So i go ahead and add the oil it needs. After playing close attention for 3 weeks, I notice i'm burning oil (about 1 quart every tank) If I didn't doctor how much oil was in the motor it'd be dry by the time I'm due for an oil change. I was told by a mechanic friend that could be possible PCV valve, I check and it's bad (replaced 135k) Continues to burn oil. I try a quart of lucas oil stabilizer due to rough running and add a heavier weight 10w-20 m1 full synthetic high mileage. Still burning oil. I ask another mechanic about the plenum gasket, told that 1st gen 4.7L don't have them as the intake is a one plastic piece. I also have white smoke coming from my tailpipe after i changed the PCV valve, smells sweet like coolant. I'm mechanically inclined, so shoot me what you think it is. Thanks in advance.