Why blue smoke?

[Mastaforga]

I have a 98 ram 1500 with a 5.9 magnum gas engine. Accelerating after start up produces an extreme amount of blue smoke from the exhaust. After warm up it only smokes a little when I rev up and down. I replaced the plennum 400 miles ago and now it runs like new with no oil getting in the intake. The pvc valve is working fine. The truck only has 110k miles and I can't feel any blowby coming from the oil filler cap. What could cause this blue smoke? I heard valves guides could leak, but there is no smoke on startup untill it is reved.

 

[Graygoose]

Sounds like valve guides.

 

[Mastaforga]

Sounds like valve guides.

Thats what I was thinking. But usually when valve guides leak they will leak excess oil onto the valves and into the chamber when it isn't running and cause a puff of smoke at startup.

It's completely clean on startup. If it is the valve guides, it would really surprise me.

 

[R/T_Fire]

Verify Crankcase pressure while running, PCV valve could be clogged, as mentioned valve guides, but I would also run a compression check on all cylinders to rule out all that can be diagnosed from bad rings or combo of a bad seat or crack in the head around the valve guide. there is a ton of things it could be but compression test is where I would start. especially since it not a symptom at start up.

The only reason why I say cracked head is I had a similar issue to a Chevy truck I had where the valve guide was cracked getting oil into the intake valve which finally lead to a coolant passage cracking. at first it was blue smoke then white from coolant then total failure. Not saying its the case here just directions to look

 

[Mastaforga]

Appreciate the ideas. Time to start checking things off the list.

 

[David H]

New 02 sensors after the plenum job?

 

[dapepper9]

The cracked head near a valve guide is a very very real possibility and actually pretty common on these motors if plenum is left too long.

 

[dodge dude94]

The cracked head near a cake guide is a very very real possibility and actually pretty common on these motors if plenum is left too long.

Where is that?

 

[dapepper9]

Where is that?

********* ive gotten better about proof reading what i type on my phone but sometimes i still miss stuff.

Fixed

 

[Johnn123]

Why blue smoke? I don't think the manufacturers have perfected orange or purple smoke yet

 

[OutLore]

The cracked head near a valve guide is a very very real possibility and actually pretty common on these motors if plenum is left too long.

What do you mean - left too long?

 

[dapepper9]

What do you mean - left too long?

Plenum gasket leaks and burns oil and if you go too long before fixing you can clog cats and increase likelihood of cracked heads.

The percentage of magnum heads that are cracked when pulled off is pretty high though, like 90 some percent.

 

[dodge dude94]

Why blue smoke? I don't think the manufacturers have perfected orange or purple smoke yet

Hehehhee

 

[Merc225hp]

Why blue smoke? I don't think the manufacturers have perfected orange or purple smoke yet

Orange smoke I have seen but purple would be a new one on me lol.

 

[Johnn123]

Orange smoke I have seen but purple would be a new one on me lol.

Need to put some purple food coloring in yer fuel