[ShadowEye571]

Hi all,
Pulled my valve cover to see how much of this liquid was built up. I first noticed this when I put my finger in the crankcase ventilation going into my air intake when I couldn't find out how gas was getting into my intake and on the throttle body. It has no smell from what I could tell and when checking oil from the dip stick the oil is clean. I'll post pictures if I can.
Any help appreciated.

 

[warriorsuspensions]

To me that looks like water in the oil. What does the oil look like in the crank case?

 

[quicksilver]

I agree with the above, you've got a source of moisture causing that yellow snot to build up in the valve cover. What year jeep ya got? How many miles?

Unless I'm deceived, it looks like you have a curved intake manifold, meaning you have one of the newer cherokees, 99-01. The 00-01 had a head casting 0331 that were notorious for cracking in between cylinders 3 and 4. So bad that you can visibly see it through the oil fill hole.

 

[ShadowEye571]

2001 Cherokee sport 4wd automatic 4 door 178,000+ miles. I read about the dreaded 0331 cracking in the past, hoping to swap out once I had the money. Might not have a choice now. I couldn't see down the crankcase as the plastic fitting was giving me trouble. It was getting late so I wrapped it up. I'll look tomorrow but I'm going to assume its clogged with peanut butter like gunk like the picture of my finger. Would I be able to see the crack with just the valve cover off or would I have to go deeper? I will mention right next to the oil filter on the side of the cylinder head (I think it's called) leaks oil. Could moisture get in that way? It's odd though that I never needed to top off my oil it never leaked bad enough. The leak was there when I got the jeep. My coolant also has been disappearing after I changed my thermostat housing and water pump a few years ago.

 

[quicksilver]

From all that I've read, and from what others have reported, you can see the crack right across the head, from driver to passenger side, between cylinders 3 and 4. But if you're leaking oil out the side between block and head, then there's a good chance that your head gasket is in need of replacement. It could also be why you have missing coolant, judging by the milkshake that you have under the valve cover, and perhaps what you'll see in your crankcase as well.

You can check to see if your head is cracked aside from visual inspection by pressure testing the coolant system. You can pick up some tools to pressurize the system with air, and if you do in fact have a crack or bad head gasket, you'll hear air and liquid bubbling in random places.

You can even do a compression check on your cylinders, and if it's low, it's safe to say that it's a bad gasket at least, it won't tell ya if you have that notorious crack since I believe that one is in the cooling jacket.

Was the water pump and thermostat replacement preventative maintenance or was there a reason that you replaced those? They can leak a little bit if your not careful when replacing those items, but you'll be able to see if they are leaking, even if it's a tiny drip.

I'd say that if you're going to go through all this trouble, might not be a bad time to replace your cylinder head since they do crack with higher miles. The 0331 TUPY head was a revised casting and doesn't suffer from that cracking issue, they will also be the closest match for ignition and emission equipment found on your jeep.

 

[ShadowEye571]

I replaced the thermostat and water pump after my jeep overheated going to work. Steam was coming from under the hood from a hole in a radiator hose. After replacing that it would still overheat at idle. I replaced them hoping it would fix that. My jeep always went to 210° no matter what until the hose went out. But after driving I saw a leak coming from the passenger side bumper. I replaced the radiator and after that no more leaks that I can see. Both the oil and coolant leaks have been happening for years, with the oil being longer. I'm only confused because I didn't have any other symptoms of a head gasket or cylinder crack. The only white smoke I saw was when I pulled the dipstick after driving when my jeep was acting up. I have another post on that if you want to read up on it. You seem to know what your talking about so maybe the way my jeep started acting while driving means my head finally gave. Others have told me its possible got water in my gasoline. My coworker thought maybe my fuel system is the culprit. How hard is it to do replace the head myself? I only ask because if I hook everything up and drive it I don't want to risk damaging anything. Last time I started up it was boggling, rpm going up and down. Also the first thing I asked around at work was if anyone knew a place that would replace a cylinder head. Barely any place does engine work around here which I find strange.

 

[quicksilver]

I replaced the thermostat and water pump after my jeep overheated going to work. Steam was coming from under the hood from a hole in a radiator hose. After replacing that it would still overheat at idle. I replaced them hoping it would fix that. My jeep always went to 210° no matter what until the hose went out. But after driving I saw a leak coming from the passenger side bumper. I replaced the radiator and after that no more leaks that I can see. Both the oil and coolant leaks have been happening for years, with the oil being longer. I'm only confused because I didn't have any other symptoms of a head gasket or cylinder crack. The only white smoke I saw was when I pulled the dipstick after driving when my jeep was acting up. I have another post on that if you want to read up on it. You seem to know what your talking about so maybe the way my jeep started acting while driving means my head finally gave. Others have told me its possible got water in my gasoline. My coworker thought maybe my fuel system is the culprit. How hard is it to do replace the head myself? I only ask because if I hook everything up and drive it I don't want to risk damaging anything. Last time I started up it was boggling, rpm going up and down. Also the first thing I asked around at work was if anyone knew a place that would replace a cylinder head. Barely any place does engine work around here which I find strange.

These engines are one of the easiest to replace a cylinder head on. There are some good write ups out there to follow along with for these engines. The only way it would be easier is if the head was lighter, ie an aluminum head, which you can get, but they are big money. But if you have basic mechanical skills, you can get it done pretty easily.

Follow the troubleshooting steps to figure out if you need to do it. Do the cylinder compression check, pressurize your cooling system, pull the spark plugs and take pictures of them and post em up. Do the easy things first before diving into this task. It takes a little more time to do all of that, but it beats spending money if you don't have to.

 

[warriorsuspensions]

I don't buy water in the gas. As far as replacing the head, the hardest part is wrestling the head which weighs about 75#. If yo get a book like Chiltons or Haynes it will tell you what you need to know

 

[ShadowEye571]

I put new ones in but haven't turned it yet. Here's the old ones. They should be in order.

 

[ShadowEye571]

Been working on and off when I got the time so I'll give a little update. I swapped out my fuel rail, fuel injectors with 4 holes, replaced the valve cover gasket, and put had put in new plugs. I inspected my cylinder head over and over but did not see a crack. If there was one it's either inside or a hairline crack that I can't see. I was confused because I had no other symptoms of a blown head or gasket. My coolant was disappearing years ago when I replaced the water pump and thermostat. Enough to where I had to keep feeling it up every week or so. Got better over time. Unless its going somewhere else, my oil never looked milky even now that it's been sitting for a while. No smoke coming from my tailpipe, a little smoke coming from the engine but very thin no coolant smell but oil smell. After getting everything together I started her up but misfired badly. I got a coil pack mod so I'd have wires instead of the rail. Could have a few plugged wrong. When changing the fuel rail the connectors broke, they won't clip to the fuel injectors they just slide on. I'm thinking they aren't getting a good connection because slide up a little when pressing them in. So once the new ones come in I'll see if that was the problem or just put the spark plug rail back in. I did drive it a few feet to see if the original problem was there but it never surged so I'm hoping it was because my pcv tube was clogged. Though I'm not sure what caused it I'm afraid it'll come back.
Thanks to all who helped. If it does come back I'll likely just replace the cylinder head and replace everything on the way up. It's not a TUPY or Clearwater so if its not cracked it might one day. Give me that peace of mind.