Hi I recently purchased a used 2006 2.3L 4x2 with 150k miles. Car was not in good shape at all appearance wise but had plenty of power and pick up. I did notice that it would have a dark smoke upon startup that turned into a more white smoke after upon startup then would only happen after hitting the pedal hard. I had done an oil change at the time I purchased it. A day later I checked the new oil and it looked like there was soot inside. I was thinking it could be just the buildup from previous owner not caring for it. A few more days I check again and oil is completely black and I'm missing 1.5qts after about 100 miles. I had a friend do some work for me and discovered throttle body and intake manifold as well as PCV was completely clogged up with burnt oil residue. changed out PCV valve, intake manifold gasket, valve cover gasket, cleaned out throttle body and intake manifold. New spark plugs as well as the old one was burnt. Put in new oil again and right after it drove like a brand new truck. Unfortunately that lasted only for a day and it started to smoke and burn oil the next day I checked the oil was low again and oil is black after only 30 miles of driving. I've tried full synthetic, high mileage synthetic blend and now I'm on plain dino oil high mileage. I've tried 5-20, 5-30, and 10-30 all with the same results. I've already done 6 oil changes and so many too offs it's not even funny.

Yesterday I checked the oil and it was about 1.5 marks before I drove 20miles to my in laws where I parked incline on their drive way. When I left I started the car and it was making a chain rattling noise or metal on metal grinding with oil light on then a few seconds later it settled in but running rough.

I'm at a lost, any path forward would be helpful, thank you.

 

Welcome to the forum

You have a Mazda L engine, Ford renamed it a Duratec engine

Google: 2.3l Mazda L engine burning oil

These were used in the Mazda 3 and 5 models, so better source for info
Loads of info, but not many solutions
Seem 2004-2007 were most effected