on 1999 Ram 1500 with a 5.9 gas engine it has been using way too much oil. it was using about 2 quarts a month, then 2 quarts a every 2 weeks, then 3 quarts every week, and now it used 2 quarts on thursday, 3 quarts friday, and 2 quarts on saturday. We swithed the oil from pennzoil, to quickerstate, then to valvoline, and now we are using Cheveron Supreme in it. I need to find out why it is using so much oil. There are no leaks so I am really puzzled why it is doing it. Also, the check engine light is on, and blinks when accelerating hard. Also, it has got a bad vibration when traveling around 45 mph, and if you turn off the overdrive, it quits. would this be a problem with the trans or would it be coming from the engine? Any help would greatly be appriciated. I need this truck since we are already down a truck, so i dont want to take it a garage.

 

Hmm, the oil consumption is likely from the plenum gasket...the flashing engine light indicates a misfire, likely tune-up time - cap, rotor, wires, plugs...the vibration may be related to the misfire, at the lower rpm's of overdrive, not enough spark reaching the cylinders causing a vibration/surging/bucking sensation.

Diagnosed to the best of my abilities over the internet, at least get the engine light scanned for free at AutoZone 1st.

 

My truck had similar issues when I got it (that's why it was such a good deal heh heh), but my plenium gasket was totally screwed, and it burned a ton of oil, but the oil had gunked up the spark plugs and o2 sensors to the point that the CEL was on. A hughes plenum kit and some new plugs fixed mine right up.. oh and I just cleaned off the o2 sensors with some brake clean... fired up, good as new!

 

Sounds like a plenium to me. Mine burned oil pretty bad before I fixed the plenium. It still does to a small extent but it's acceptable compared to what it was.