Seeing that this forum was created exclusively by Jeep lovers, maybe you all can talk me out of blowing this thing up. I love this Jeep - it's the first Jeep I've owned - especially how easy the 4.0 is to work on. As a former Toyota lover (especially the mid-nineties celica-supra and corollas) I can appreciate the simplicity of the engines design and it's easily access-able components...so don't think I am just a troll. No, I really enjoy driving AND working on my Laredo. The urge to create a WJ-sponsored fireworks show is just due to my ignorance to everything Jeep ( and everything mechanical - while Im at it...working on cars just became a passion of mine ) so I'm akin to the toddler who throws his toy car because one of the wheels stopped spinning. Anyways, that being my introduction here is my question:

Why is my oil creamy brown?

I've read multiple threads on diagnosing the creamy-colored-oil issues, but I don't feel like those answers fully pertain to my problem. Most threads indicated that one day the car started acting funny, they checked their oil and - lo and behold - they saw coffee. I too saw this and took steps that I thought would fix the problem, but my first test drive after "fixing" it, I pulled over after not even 2 minutes of driving to discover coffee on my dipstick again! 2 MINUTES! I have a 2004 Jeep Cherokee 4.0, and upon discovering this contamination of my oil the first time I did the following: 1. Drained all of my oil. 2. Took off and cleaned all components from the cylinder head up. 3. Installed new headgasket (although I couldnt see any blown or heavily worn areas) 4. Reused the valve cover gasket but applied copper gasket sealer. 5. Inspected my oil pan after refilling my cooling system to the top ( to check for any water ) 6. replaced oil filter and added new oil. 7. Took it for a spin.
Like I said, not even a two minute drive and I discover creamy colored oil yet again. No performance issues, just cream. So it leads me to think that a water passage might have somehow leaked into an oil galley (is that possible?) in the block or head...also I noticed my valve cover wasn't properly tightened (I could hear a whistling noise while driving) and I tightened it promptly - could an air leak into the valve cover produce oil in that color? thanks

 

Welcome to CF!

First, I'm going to ask YOU a question. Are you sure you have the original engine in it? NOW a little history to show you why I asked that.

In 1999, Chrysler redesigned the cylinder head for better port flow, but in doing so, they created weak spots in the metal that cause the head to crack. This is the infamous 0331 head. Chrysler never admitted they had a problem, but for 2002 and beyond, they had it cast in Brazil to make it stronger. This is called the "TUPY" head. It's still a 0331, but is supposedly stronger.

Where these heads usually crack is in between the #3 and #4 exhaust valve springs and it allows coolant to enter the oil. This crack can be seen directly below the oil filler cap. I got lucky with my 2000 because it cracked into the exhaust port and NOT into the oil so I caught it before to ruined the bearings. The new Chrysler 0331 head has "TUPY" cast into the head in this general area.

NOW, it's possible the new "TUPY" head has a problem as well, but nobody has yet the post about one that did. When I fixed mine, I bought a "Clearwater" head from Odessa Cylinder Heads in Clearwater FL. It's a heavy-duty casting that actually weighs 8 lbs more. $455 with free shipping if you have to go that way.

The "coffee" color is generally caused by water and carbon in the oil, but you're running a yellow coolant, right? My 2000 still uses the old green stuff. Drain a sample of oil from the pan into a glass bottle and let it sit for awhile. If it's coolant, it should separate.

I can't think of any other way you could be getting coolant into the oil so quickly than from a cracked head. Don't shoot the messenger!

 

Thanks for the reply!
Smh...your quote about stupidity is ringing through my head right now...
I did see a few mentions about this 0331 but because I have a friend who owns a shop (and has resurfaced parts for other friends of mine), I never gave the head more than a quick once-over before handing it over and trusting his findings. But your description of the head cracking between the no.3 and no.4 cylinder seems dead-on due to the deposits that I discovered on the headgasket and on the surface of my no.3 piston. I just thought that a defective gasket caused this, but I'll have to take a closer look at it today. While I'm at it I'll post back the cylinder head and block model, but I've read that the 0331 cracking issue is common with the 00-02 years, whereas I have an 04.

ALSO: I was running it with water in the cooling system in anticipation of having to drain it again ( no confidence lol )

 

As I said, the 03-04 is still a 0331 head, but has a "TUPY" molded or stamped into it.

 

My (used)2004 had 2000 engine with non-tupy head!
I replaced it with a newer engine and a month later FIREWORKS....it caught fire and was totaled!

 

when i rebuilt my motor the head looked fine to the naked eye but when i had the machine shop mag it they found a crack in the head. i replaced it with a TUPY head i got from cylinder heads international, ran me $450 with free shipping and so far havent had any issues. the only thing id be worried about other than the head is how the bearings are because coolant will wipe them out fast.

 

BTW, TUPY S.A. is a cast iron foundry company in Catarina, Brazil with new facilities in the US. They make castings for the worldwide market.