blucllrmn

I have a 1992 Cherokee Laredo 4.0 inline 6.
I was getting tires& shocks on her when the mechanic told me the oil was low
and milky. I was puzzled because I just did a tune up and changed the oil.I check myself and the oil was extremely low so I put in a couple of quarts and drove home. I checked the oil and it looked fine . In fact the Jeep ran top notch and the ride was SWEET !
The next morning I was warming it up as the temp dropped to 20 degrees or so over night with wind chill below zero. The engine over heated with coolant coming out of the radiator cap and steam out from around the thermostat housing. This prompted me to double check the oil - milky on the bottom of the dip stick -just on the bottom .I understand this typically means a blown head gasket or cracked head/block. My question is can the milky oil be cause by something else other that head/ crack or gasket?
I haven't done a compression check yet and I'm a little stumped at the engine performance. Any help would greatly be appreciated !

Larry's XJ

This kind of the wrong forum section for this kind of question. Maybe a mod can move it.

As to the ??? Overheat may have been from frozen coolant if it wasn't up to snuff. Which in turn may have blown a gasket or cracked the head.
Hopefuly this isn't your only ride as you need to do some testing and repairs. As odds are it won't last long at all as it is.

blucllrmn

Yes I know I have some work to do. *sigh*
I apologize for posting in the wrong section . If you tell me what section might be better I will delete this and re-post it there.
Thanks for your prompt reply.

Larry's XJ

No appoligy needed. I reported it, and it got moved
Bummed that no one else repplied since yesterday.
So I'll flap my lips some more.

Overheat may have just been stuck thermostat. Could have been one time fluke or not. Consider testing thermo or just buy new 195*
Get an antifreeze tester, couple bucks at auto parts. Maybe fill rad, start up and keep close eye on temps, shutting down before boil over if it starts to get very hot. When it overheated did you by chance start it then go back in house to let it warm up?

Have you checked oil since overheat? Full or down? Any milkshake on stick?
Look inside oil fill hole, any MS?

If it's still cold where you are, look in rad and overflow to see if coolant looks froze.

If stat and coolant checks out and still over heats, get tester for combustion gasses in coolant.
Is this thing throwing any codes? CEL?

Next up would be compression and/or cyl leak test.

Fred/N0AZZ

Where else would he post his question other than here??


First off go to AutoZone and rent a leak down tester and see if you can find where its leaking water and oil into one another then a compression tester for starters. If unsure on how to use these tools, or don't have tools yourself to work on an engine you need to find a shop to help you find the problem.


You do have a problem and the engine is in bad shape with water in the bearings for any length of time. If its really is shot you might shop for a rebuilt or used engine (buyer beware always).

Larry's XJ

Originally posted in "build" section.

blucllrmn

I would like to thank you both for your help.
I went out today to double check the oil/engine.
Once again the oil looks fresh -and it is fresh.
No milky residue on the dipstick ,just a little sludge on the very tip & only on one side. A little milky residue on the inside of the oil fill cap on the valve cover but not inside . There doesn't appear to be any oil in the coolant.
The engine preform top notch as I just tuned it up . No steam coming out of the exhaust either
I'm not so sure what happened?
The temps here are sub zero overnight with wind chill -13 or more.
Yes I left it running & went into the house.I just had the coolant system flushed and a new heater core installed by a reputable ford service tech. He mentioned something to the effect of not being able to clean it out well. So I will be replacing the radiator ,hoses etc.

I bought a compression tester and I'm pretty good with tools and have LIMITED mechanical skills & knowledge .

Larry's XJ

Somewhat good news.
Just keep checking, testing, keeping eye on things.
Check out the "Tupy head" thread. Some good info/ideas which some may apply to you. https://www.cherokeeforum.com/f2/que...-heads-205310/

Must be in more northern climes than I first thought, though it got to -25 last night here, N. of DEEtroit a bit.

Bustedback

Do you make short trips and never really get the engine to operating temperature? If you're only driving a few miles and let the Jeep sit long enough to cool down and then drive home and shut it down for the night you will get condensation that builds up and leaves a milky sludge on the oil fill cap. If that is the case take your Jeep out for a long drive once a week and let it get up to operating temperature long enough to boil the condensation out of the engine.

HudsonN

Just for reference here's what my jeep looked like when i pulled the valvecover off when i had a cracked head.

blucllrmn

It's my only vehicle so I drive it everywhere.
The weather has been a little warmer/milder than usual this year and we hit a cold snap. I have never seen anything milky until the other day & now that's seems to be cleared up. I don't think The oil fill cap is seating correctly.
The oils is just as clear as when it came out of the container.

blucllrmn

Just an update . The Jeep over heated again -the thermostat housing will not seal correctly and water seeps out at a good rate. I replaced two gaskets. A little milk shake on the end of the dip stick again ,it wasn't not there this morning.
Did a dry compression test all cylinders hit 120 with one at 118
I wont be able to do the wet test until Thursday. I'm going ice fish tomorrow instead
of working on it

Radi

Can't pressurize the system with a big leak, could well cause an overheat. Radiator cap and/or filler neck might have issues too if coolant is blowing out of there.
Run Shell Rotella in there to clean up the sludge in the motor, and your compression numbers are fine.

Fred/N0AZZ

Replace T-Stat housing first then go to an AutoZone and rent a Leak Down Tester. When pressurized start listening for any leaks need quiet area and mechanic headset, do watch for any leaks on the outside as well that is where I would start.


Anytime oil is milky a sure sign of problems that need to be addressed quickly.

centuryhouse

When I had a blown head gasket it would overheat if enough fluid had leaked into the oil, and the oil was muddy / milky, but otherwise it ran just fine.