2012 Ram 135K-Sudden Lifter noise-loss of power-loss of 5mpg-misfires under load

What is your question?

I have a 2012 2 door Ram 4x4 5.7 Hemi, 135,000 miles. 5 days ago, a lifter started ticking. I drove 300 miles up into Washington. On the freeway, I normally barely touch the gas and it goes. This time, I pushed it and then it would drop down to 4th or 5th. Gas mileage is normally 18-19mpg. It was under 13mpg. I had just changed the oil and cleaned the K&N air filter before the trip. I re-cleaned the air filter as I thought I might have put too much oil on it. I normally don't soak it. I headed back home the next morning. It seemed better until I got back on the freeway, then the same thing. Got 2/3rd the way home and gave it some gas and the engine started shaking like running on 7 cylinders. My Check engine light came on. I eased up and it smoothed out. I eased it on home watching the gauges. Checked for codes and got P0305-misfire 5th cylinder. I went on line and found bad lifter that can damage the cam and broken valve spring. A lot of others had the #5 cylinder death as well.

What makes this problem better or worse?

worse when under load

How long has your 2012 Ram 1500 had this problem?

5 days