Milky Oil Cap

[Duneger]

Replaced the engine in my Libby with a used, "good" engine off eBay.

Drove it for 1000 miles around town 10-30 minute trips. Noticed the oil cap was fairly covered in milky white goo. Flushed the oil with Liqui Moly engine flush and changed the oil. No coolant loss from initial fill level.

Went for a 1200 mile rode trip, no milky white substance on oil cap. Changed oil just because I was still 50/50 on it being a blown gasket or cracked block. No coolant loss.

500 miles of 10 minute commutes to work. Huge amount of white goo on oil cap and a crud ton of condensation on oil cap. Padded cap with a towel and the condensation was straight water. No coolant smell or color to it. Still no coolant loss.

I noticed a leaky valve cover gasket dripping oil onto the exhaust. As I was replacing the gasket, I notice the valve cover was bent up pretty bad in a few sealing areas. Could the PCV system pulled cold moist air into the valve cover, condensed and caused the white goo?

 

[kejobe]

A milky oil cap and no coolant loss is normal for these motors. It's condensation. It happens on mine also.

 

[ltd02]

A milky oil cap and no coolant loss is normal for these motors. It's condensation. It happens on mine also.

Yep and short trips in cool temps don't give the water vapor a chance to distill off. Long trips no problem. I've found synthetic oil helps but not all that much if you are stuck with a short commute.

 

[tommudd]

Short commutes are killers on these motors.
I've never had any issues at all on any of mine, but since my 91 year old step Dad is driving the 05, well there are issues in the cap.
But the ones I drive nothing, but then they get run and run hard daily and warmed up good

 

[04Liberty]

That's the high point in the system, any condensation that even has a chance of trying to burn off on your 10min commutes (with no pre warm up time, I'll wager, just start and go like most people today lol) will gather there and it will continue to do so unless you take the poor thing out on the highway at least twice a week and do some higher speed runs to really get some heat in the engine.

 

[LibertyTC]

Ya short drives not good, always allow the Jeep to fully warm up to operating temps, before shutting it off. Highway drives are good for the Jeep, city driving ah.. not so much.
How 2 get rid of the milky goo..Link: http://www.jeepkj.com/forum/f196/pcv-positive-crancase-ventilation-tsb-59367/
Also Link: http://www.jeepkj.com/forum/f202/upgrade-your-pcv-system-tsb-25-001-08-a-59416/
Come winter, I allow the Jeep to warm to 170F before driving off, that is just below the half mark on dash temp gauge.
It is also good for the battery to have a straight 25 minute charge minimum wherever possible.

 

[Duneger]

Alright, that makes sense. There is a viscometer at my work, so I'll do rheologies on the oil before and after to get a better sense of when to change it.

The weird thing is it just seemed like the original engine didn't get milky at all. Oh well, it's probably due to the changing weather and shorter trips like you guys said.

 

[Joenavy85]

Yep, as LibertyTC said, PCV valve. I started getting the milky crap on my cap a while back. My drives to work take about an hour for 32 miles, engine gets plenty warm, so I replaced the PCV valve and about 6k later it hasn't returned.

 

[Aceofspades]

As soon as it’s cold here - the 02 gets filthy under the cap regardless of driving. Unless one or 2 short trips outweighs the 20 longer ones ?
The 03 has the plastic baffle in the oil filler neck and doesn’t get as dirty. Both have new pvc in the last year or so. It’s the only difference I can see.
Also it’s been mentioned to me before to upgrade to the newer style pvc system. There’s a write up.

 

[kejobe]

As soon as it’s cold here - the 02 gets filthy under the cap regardless of driving. Unless one or 2 short trips outweighs the 20 longer ones ?
The 03 has the plastic baffle in the oil filler neck and doesn’t get as dirty. Both have new pvc in the last year or so. It’s the only difference I can see.
Also it’s been mentioned to me before to upgrade to the newer style pvc system. There’s a write up.

I took that baffle out and threw it in the trash. Didn't like the fact that I couldn't get in there as easy to clean the milky crap out.

 

[HoosierJeeper]

I think that baffle is there to protect the PCV during oil changes/ adding oil

 

[LibertyTC]

Yes if you have the pcv mounted to the filler neck, leave the baffle in, otherwise you will soak the Pcv valve.

 

[kejobe]

Yes if you have the pcv mounted to the filler neck, leave the baffle in, otherwise you will soak the Pcv valve.

Meh. Mine's gone and haven't (yet?) had an issue and my PCV is in the filler neck.

 

[Royy]

I used to get A LOT of this milky crap in the oil filler tube, no matter how often I replaced the PCV valve. Then I converted the entire PCV system to the 2006+ setup mentioned earlier in this thread, and that completely solved the problem. No condensation or goo of any kind since then.

 

[J33Pfan]

Just for info: My 2002 V6 4WD built 2001 has the baffle. at 165k miles theres no milk and the car runs short trips daily. Standard PCV system.