Compression Question

[MtnClimber]

Howdy All,

Specs:

88 MJ, 4.0L, 5speed, 4X4

 

I have a 95 VC on it, allow it to vent into the airbox. Milky oil is coming from it saturating my air filter. Milky oil is also present on the oil fill cap.

Plugs are all burning equal, no visible bad signs there.

Coolant is super green. No loss of coolant is visible.

Oil is fine. Performed an oil change, drove it a hundred miles, no sign of coolant in it.

 

Compression specs:

Cylinder Dry Wet PSI Difference

#1 110 125 +15

#2 130 140 +5

#3 120 140 +20

#4 125 130 +5

#5 135 135 +0

#6 90 105 +15

 

 

Looks I have a ring issue in Cyl#6, but that doesn't explain the milky oil. Any idea's?

 

Thanks in advance!

[HOrnbrod]

Pull the rear CCV elbow on the valve cover and check if the metering hole on the bottom is clogged. Also do the same for the plastic hose from the CCV elbow to the intake manifold.

[jimoshel]

Milky oil means coolant is leaking into it. Might have a leaking head gasket around no 6.

[MtnClimber]

The rear CCV elbow goes to the intake manifold. Can this be eliminated altogether?

[mnkyboy]

Milky oil means the presence of water in the oil , not necessarily coolant.

 

Vehicles that that sit alot, especially on grass and in wet climates can build condensation which can get bad enough to give you milky oil.

Also vehicles that don't get properly warmed up often will do it because they don't ever get hot enough to burn off the gathered moisture.

Often a good drive will clear it up.

 

I'm not saying thats the case here but its good to know when troubleshooting.

[MtnClimber]

Thanks. It runs around 180-190 degree's on the highway (60mph). It's been zips @$$ cold up here for the past few weeks, so maybe that'll present moisture in the valvetrain. And there's plenty of moisture up here with all the lovely snow!

[Eagle]

The rear CCV elbow goes to the intake manifold. Can this be eliminated altogether?

 

No.

[HOrnbrod]

The rear CCV elbow goes to the intake manifold. Can this be eliminated altogether?

 

No, this will make the blow-by into the air filter worse by increasing the pressure in the cover. Sometimes you can clear the hose and elbow metering valve by pushing a wire through, but not usually. The normal fix is to pull the cover, clean the gunk out of it including the vent towers, and replace the rear elbow and plastic hose.