KyleCross1468
Junior Member
I have a 98 1500 with the 5.9 magnum. It has 192k miles on it and on first startup it makes a slight haze for a second of bluish smoke then stops. When revved up or accelerating thought it blows a good bit of smoke. I did a compression test it has 155psi and above in each cylinder. Also noticed that sometimes when idling it will start rough idling and making a loud hissing sound from throttle body intake area. I know the plenum gaskets are a big issue I looked into throttle body it has some shiny oil gritty ness in the bottom but hard to really see. I think I can rule out rings. I’m just trying to see if plenum would cause that smoking and valve stem seals aswell? It runs fine starts up has a slight miss every once in a while but other than that is great. Any help would be greatly appreciated. Thanks.
