Need help!

[socalexpe]

So bought this 2004 5.4l 2V EB 4x4 128,000 miles. Truck runs solid. Drove it this week from California to Tennessee. Crazy weather all the way down to 2 degrees, storming with snow hail and rain. I changed the oil and filter out about 2k miles on it after buying it before heading out. When I got to Alabama the oil cap was like a vanilla milk shake and the oil on the dip stick kinda milky 2000 miles after the last change. Changed oil then drove another 500 miles and not so much. I believe the intake is leaking cause when there is a load and the truck it defaults to defrost. I changed all the vacuum lines so there is no vacuum leak before I left still default over a load though. Could it be the cold weather doing this cause of the vacuum leak not allowing the engine to vent properly? There are no misfires. Engine has a lot of power and no coolant loss. Need help to point in the right direction. Thanks

 

[99WhiteC5Coupe]

So bought this 2004 5.4l 2V EB 4x4 128,000 miles. Truck runs solid. Drove it this week from California to Tennessee. Crazy weather all the way down to 2 degrees, storming with snow hail and rain. I changed the oil and filter out about 2k miles on it after buying it before heading out. When I got to Alabama the oil cap was like a vanilla milk shake and the oil on the dip stick kinda milky 2000 miles after the last change. Changed oil then drove another 500 miles and not so much. I believe the intake is leaking cause when there is a load and the truck it defaults to defrost. I changed all the vacuum lines so there is no vacuum leak before I left still default over a load though. Could it be the cold weather doing this cause of the vacuum leak not allowing the engine to vent properly? There are no misfires. Engine has a lot of power and no coolant loss. Need help to point in the right direction. Thanks

You may have a clogged PCV valve. Replace it. Ensure the rubber PCV grommet is not hardened, shrunk and leaking.

A vacuum leak should not cause the milky oil - which is a sign of condensation not boiling-off.

 

[socalexpe]

You may have a clogged PCV valve. Replace it. Ensure the rubber PCV grommet is not hardened, shrunk and leaking.

A vacuum leak should not cause the milky oil - which is a sign of condensation not boiling-off.

I changed the PCV valve with the vacuum lines. So what your saying is the grommet on the valve cover to be changed aswell?

 

[99WhiteC5Coupe]

I changed the PCV valve with the vacuum lines. So what your saying is the grommet on the valve cover to be changed aswell?

I would at least check it. They tend to dry out from engine heat, harden, and shrink - which allows a vacuum leak (and doesn’t fully allow the PCV valve to work properly).

One other thing to check - is there a code set for slow engine warmup? If so, that means the engine coolant thermostat is stuck open, allowing the engine to run cooler than it is designed. That can cause milky oil residue, especially on shorter vehicle trips. I know you said you had a very long drive.