Hello my name is Joshua, I'm having a bit of an issue with my 5.3l. Its an 02 block with all 07 new body attachments, heads, timing cover, water pump etc. I just did a cam swap and got rid of the Dod. Everything but the piston rings, pistons and crank shaft is new. There's no over heating at all, the thermostat is opening as it should, and the oil isn't milky even a little bit. But once it gets to operating temp it erupts with smoke, big puff of smoke from under my hood and continues to idle just fine. There's no smoke out the tail pipe ever. Upon inspection the oil dip stick tube has some smoke coming out of it and my valve cover gaskets have been blown out on the top side of the valve cover, then a minute or so later it puffs out a giant cloud of smoke again from under the valve covers but continues to idle with no hesitation and no smoke out the exhaust. I've checked the pcv valve and even cleaned it after finding that it still works. I'm absolutely lost as to what this could be as the leak down test says my cylinders are sealed up good. What could be causing this huff of smoke every minute or 2?
AFAIK modern cars ventilate combustion gases from the block/valvetrain to the intake system (to meet environmental issues) by a breather.
Is this disconnected / blocked on your car?
And: excessive blow-by in the cylinders is not good. Maybe the pistons/rings were due too?
PCV valve is working and also cleaned out. I'm going to do another leak down test tonight and compression test to check those piston rings so I will update later tonight.
Pcv valve I working, leak down test was solid and the compression test showed every cylinder was just under 120psi