My 2006 300C with a 5.7 currently is sitting at 194k miles. A reman motor with 40k miles was put in about 10k miles ago, and completely remanufactured heads were also used. At the moment, I have a warm start blue smoke issue from the tailpipe and it will also let out a puff after idling for a few moments, or upon deceleration such as on a hill. Seems like the classic symptom of valve seals, but I have my doubts considering the age of the heads. The car runs pretty well, with no codes, but will idle rough after a bit, likely due to the plugs and intake charge being fouled with oil. Oil consumption is about 1 quart every 600 miles. Oil pressure is great, and when cruising, there is no oil smoke.

The dealer is noting that the intake gaskets are leaking, which is visually evident by the oil residue on the heads. Could this be a cause of the oil consumption and smoke? Always considered it to potentially be a intake gasket issue.

The lifter valley is sealed on a G3 and each intake runner has its own o-ring seal,so there is no real source for oil to be pulled into the intake..The oil fill tube does pass through the intake itself,that could seep oil externally.

I would check out the PCV system and make sure everything is right there.

Thank you. This is as I suspected. My experience is that the G3 5.7 intake gaskets are pretty hard to install incorrectly as well. I suppose anything is possible, considering that I did not rebuild the engine myself.

Put a new PCV valve on it a few weeks ago, with no help. I also put a small generator water separator in between two hoses to act as a catch can so to speak, to see how much oil was making it through. On a hard drive (about 50 miles), that separator, albeit small, as halfway filled up. There must have been some condensation at first, as there was a bit of milkshake at the top of the oil in that separator. It had not been run in a while before I took it for that drive.

Oil in the crankcase and on the dipstick does not show any signs of water making its way in, and the coolant temps are always at normal temp around 203 degrees.