Blue smoke after warmup

Discussion in 'Troubleshooting & Diagnosis' started by Doruntrus, Jan 27, 2018.

  1. Doruntrus

    Doruntrus New Member

    Aug 7, 2014
    Springfield, MO
    Hi all, I have a minor issue that I was hoping to get some experienced input on. I'm getting blue smoke from the passenger tailpipe as the engine starts to warm up to temperature. It doesn't happen on initial startup.

    The car has sat for a while, with only being started a couple times for brief periods over the last year. I put on a new intake, headers, and dual exhaust in that time period, as well as replacing the driver side head gasket. It didn't smoke beforehand, so I'm hoping that it's just due to sitting so long and maybe some oil finding it's way into the headers. But I'm paranoid and was hoping to get an opinion from some of you more experienced guys, lol.

    I realize that it could be rings or valve stem seals, but it just seems unlikely that those would manifest after a period of sitting.
  2. Zspoiler

    Zspoiler Veteran Member

    May 6, 2012
    Federal Way, Washington
    Its not the headers.Did you have the heads rebuilt ,It could be the valve guide seals need replaced ,
  3. Doruntrus

    Doruntrus New Member

    Aug 7, 2014
    Springfield, MO
    I definitely did not have the heads rebuilt, unfortunately. Since I'm hoping to start putting together a new 350 soon, can I just run this for now if it is the valve guide seals?
  4. Zspoiler

    Zspoiler Veteran Member

    May 6, 2012
    Federal Way, Washington
    Just watch your oil level and don`t run it to much if you can.because it will foul spark plugs,
  5. COPO

    COPO Veteran Member Lifetime Gold Member

    Sep 15, 1999
    Ontario, Canada
    Use extended tip plugs (I.E. R45S) if you have flat tops.
  6. 71RS6SPD

    71RS6SPD Veteran Member

    Nov 14, 2016
    Don't start an engine for brief periods. Most engine wear occurs during warm up. Plus it leaves moisture in the exhaust if it does not get hot enough to boil it out. Bad valve seals or valve guides will smoke mostly at startup and upon deceleration. Smoke during acceleration is most often bad rings. If you have another motor... drive it!
    Smokey15 likes this.
  7. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    Nov 4, 2004
    Ringgold, GA
    If this condition started after you replaced the intake, I'm betting on the intake gasket. If it's not fouling the plugs or bothering you too bad, just drive it until you get the new engine. IMHO
  8. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN

    True dual exhaust and smoke only on one side... Very likely the intake gasket is allowing it to suck a bit of oil from the lifter valley.

    If you pull the plugs, you'll probably be able to see one or two of them getting oily.
    You might want to re-torque the intake bolts (Center ones first) prior to pulling the intake and attempting to reseal it.

    Good Luck!
    Knuckle Dragger and Smokey15 like this.
  9. Smokey15

    Smokey15 Veteran Member

    Aug 13, 2017
    Last 2 posts = agree.
  10. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    Jun 22, 2003
    Endicott, NY
    Man, this is a tough one without being there!

    Could be bad PCV sucking oil in. What intake gaskets did you use and were they the correct port size? Warped intake (seen it on a NEW Edelbrock intake!). Did you put Permatex #2 on the intake and head bolts when you installed them?

    IF it were the valve guide seals, it might not smoke on start up. IF it is the valve stem seals, buy a set of small block Ford umbrella seals and install them along with the stock "o-ring" seals (it's a good Band-Aid fix that will get you by for now).


    The last guess that I have is that the oil return holes in the head(s) are plugged/restricted so that when the engine runs for a while, the valve covers are flooded = the valve stems are DROWNED in oil = oil is sucked down the guides = engine smokes.

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