I just did a total rebuilt on my 2.3L Duratec engine in my 2007 Ford Ranger and with less than 7,000 miles on the rebuild it started blowing white/blueish smoke. I removed plugs and cylinder 4 is dead from oil. I replaced all the valve seals/ spark plugs and then started it up and it is still blowing smoke. So I remove cylinder 4 plug and it has fresh oil on it. I then do a compression test on cylinder 4 and compression is really good. I then disconnect the PCV valve from the intake manifold, plug the manifold where it hooks up and start the truck and it is still blowing smoke. So how do you think oil is getting into the cylinder?

Thank you for your time.

 

Just a thought, who did the rebuild and what is the experience level ?

Almost sounds like the Oil rings on cylinder 4 either spun and aligned, or install was a little off.

Ltr

 

I built it and it has all new pistons/rings of very good quality and all rings were installed the right way, I am meticulous and I have built many engines and never had a ring spin or break, this is just my pest control truck so no high rpm going on either. My gut is telling head gasket.