I have some milky stuff on the 4.0 engine oil dip stick. I've watched the coolant level etc, and haven't seen any loss of it. And no bubbles in the coolant in the radiator.

The dip stick has been like that for a couple months, and when I changed the oil, it looked normal.
Not to muddy this up, but I had a Pontiac years ago that always had that stuff on the dip stick, which rusted it.

Any ideas ??????


Bill

 

Milky stuff on the dipstick means water in the oil. How it got there is another question.


You probably have a blown head gasket or a cracked head. Face reality now, or face it later. There was a thread here just a couple of months ago with someone insisting his problems could not be a cracked head. He was adamant it couldn't be a cracked head. The thread turned into a "how I rebuilt my engine and replaced my cracked head" thread. He did a great job on it, too, once he faced reality.

You can find out for sure by buying a test kit at your local parts store. Tell them you need a test kit for combustion gasses in your coolant.

 

This is Michigan. Short trips? Condensation is most likely. The oil cap has the same stuff on it.

 

It could just be condensation. If your coolant level is normal and stays the same, I would just keep an eye on it for a while.

If it's the same way next summer, or after a long high-speed trip, I would start a diagnosis at that point.

 

When I bought mine the P. Owner took the jeep swimming at the lake they were camping at. Sand was all the way up into the glove box. I still bought it from him. For the first two years I had the same milky dip stick. After several oil changes with oil treatments before the changes, everything seems good.

 

is there just milky stuff on the dipstick or is all the oil milky. there is a huge difference between the two..

 

• Milky oil means there is water in there. That water is damaging your bearings, regardless of how it got there.
• If you have enough condensation to make milky oil, you have serious problems.
• Leaving that condition alone until next summer is likely going to mean an engine rebuild.
• Not all head gasket leaks result in a loss of coolant, and it doesn't take much to start damaging your bearings.

For the risk of the cost of an engine rebuild, getting an exhaust gas tester is cheap insurance.

 

Thanks for all the replies. And thanks for the link to the tester. Not a bad idea to have one of those around anyway......

 

That is why I used a treatment that you put into your oil and run the engine for a short time (a day or two). Then do the oil change. I did that for a couple oil changes. Now the oil looks good and has been good for the last year or so. I figure that I will run this engine until it crooks and go from there. I wish I could take my son XJ and steal his engine. That thing purrs like a kitten and runs like a bat out of hell.

 

As I interpreted your earlier post, there is a milky (residue) on the dipstick (above the oil line) and on the underside of the fill cap (but none apparently anywhere else).

If that is all there is, I still maintain that it is too early to start ripping into the engine.

You said the oil looks normal on changing it, and the coolant level remains steady. If the engine maintains normal temps and oil pressure, nothing really definitively points to a head gasket failure at this time.

 

I have a 85xj with the 2.5L and I get the same residue on the dipstick. The coolant levels have stayed the same for two years without loosing any and the oil looks good when changing it. I do have quite a bit of blow by due to worn rings, you can pull the tube from the inlet side of the valve cover that connects to the air cleaner and feel puffs of air against your hand even with the carb pulling through the pcv line.

If I connect a line directly to the carb without the pcv valve and plug the inlet connector the milky residue on the dip stick goes away because I am pulling a strong vacuum on the crank case which dries the condensation from the blow by.

If you are getting a lot of blow by it could be what is causing your problem. Blow by and short trips really compounds the problem as the moisture from the exhaust never gets cooked out of the crank case, and cold weather will compound it again causing worse condensation. Do check for exhaust gasses in your coolant, that shouldn't cost too much, but also check to see how much blow by you have. Could be you need rings, but that is less of an immediate concern than at cracked head or blown head gasket would be.

 

The oil on the 4.0 that I returned yesterday didn't show signs of any issues on the dip stick or on the oil that I drained out of it after taking delivery. It was until I changed the oil I read about the cracked head syndrome and started looking in the oil fill hole. There was some soft sludge between 3 & 4. Looking at an angle towards the push rod on 4 I could see green droplets. I pulled the valve cover and saw some droplets further up on the head. I wiped the whole area clean and and see any crack. I put the cover back on and fired it up to move it.behind the garage. I got out and looked down the oil fill hole while it was running and low and behold I started to see a droplet of liquid form ever so slowly and it wasn't oil.

 

Can also be caused by excessive blow by, how many miles on the engine?

 

Well he's got a 2000 XJ with the 0331 head. They all have a factory casting flaw that shows up as a crack between #3 and #4 valve pockets.

 

If you want to be sure what's in your oil, order a test kit from Blackstone. Then go drive the Jeep around for 30 minutes (to burn out condensation), take a hot oil sample and send it off for analysis. The analysis will tell you if you have an issue.

What brand and flavor of oil are you using?

The "milky oil" test doesn't work reliably any more. Forty years ago water that got into oil would emulsify and make it turn cloudy. The detergent packages in oil have gotten so much better since then that the detergent bonds to the moisture to prevent it from turning cloudy. So now you can have a lot of coolant in your oil without being able to see it.

I was running Mobil 1 when my head cracked. It turned a little lighter in color but never milky or frothy the way it would in the 1970s.

I'm not sure from your post whether this is your Jeep or one that you were considering buying and returned instead. If this is yours, you need to swap that head as soon as possible. As soon as you have coolant in your oil, it is causing bearing damage. What's basically just an afternoon's work now will turn into a replacement of the long block if you let it go.

This thread is confusing. It looks like Steelybill (the OP) has a '94, for which a cracked head would be unusual. 51 Ashton is the one with the 2000 with an observed head crack, which is not unusual. Let's be sure to clarify which one we're talking about, lest we confuse the hell out of someone (me).