Ive got alot of smoke coming from the dipstick tube. Its also idling abit rough. Alot of black smoke out the tail pipes if I floor it. Its not missing or anything. Any ideas, I know it cant be good.

 

replaced your valve seals recently?

 

No, just replaced intake manifold gasket, thats about it. Think it might be a bad valve?

 

valve SEAL. Little seal thing inside of your spring. All 16 seals from GM cost about $30.

 

How hard is it to replace these? What needs to come off?

 

I would suspect blow-by from poor ring sealing before suspecting anything with the valves. The valve seals are more for oil control. The valve seats would have be leaking for any gases to get up through the valve guides and into the valve cover area. Seals are not going to fix that.
I would do a compression and leakdown test to check the health of your engine and help determine what is worn.

 

Remember the PCV system vents Positive Crankcase Pressure so the crankcase is always negative pressure. That is, VACUUM. If the PCV system is not venting properly, the result is high or not low enough pressure. Try replacing the PCV valve. Then if need be start testing. It only requires a manometer. Start the car and then hook up the manometer, not before.

BTW, valve seals do not cause blowby. If the valve seals are bad, it would smoke out the pipes cause it would be burning oil.