nickengels

I have a 2000 Cherokee Classic 4.0L with 104k on it. She runs solid but i keep having to add oil every couple of weeks. ( keeps dropping to add on the stick) When i got her i had the valve cover gasket and the gasket to the oil filter mount replaced. Doesn't appear to be leaking, no spots on the pavement. Need some help to troubleshoot this out. Do i have a leak that i can't see, or am i in fact burning oil?

Ye Ol' Cherokee

Hard to tell without looking at it, but here's what i'd advise you to do.

Get a really big piece of cardboard/many pieces of cardboard laid out, and lay it out in your driveway/parking spot to be about the size of half of the jeep (From front bumper to like the back door.

Drive the Jeep and get it to full operating temp. Go on the highway, run it for a while, whatever. While its nice and hot, park on top of the cardboard, and make sure there are no gaps. If there is after you park, put another piece of cardboard there.

Wait a while, and observe as it cools, and see if anything ends up on the cardboard. If there is liquid and you cant tell what it is, wipe it up with a paper towel and give it a sniff.

Other places to check with a flashlight and a cloth/or finger is the rear of the valve cover gasket. Prone to failure from what i have heard, and mine has failed back there in the past. Also just look around the engine bay very carefully and look for moisture.

Check the coolant for oil as well

nickengels

ill be sure to do that. I just took her to the self wash and power washed what grime and grease was left on the motor from the oil filter mount gasket leaking. now with that being replaced ill be sure to watch and see if any residue appears. I do know that the casting on the head of this era was weak and prone to crack, but i doubt that is the issue. I was told the oil additive restore was pretty solid so I'm gonna give that a shot and see if it can help out.

nickengels

On a side note, i did just have the coolant flushed few weeks back, it was much needed. There doesn't appear to be any mix of oil in the coolant. Its nice and clean.

01SiennaXJ

X2 on the cardboard.. It helped me pinpoint my oil leak pretty easily. I've heard great things about the engine restore oil additive as well.

Is your coolant level dropping at all?

Roler

How much oil do you have to add?

The cardboard is nice, but doesnt say anything about the lcoation of the leak.
To give you an idea: oil leaking from the valvecover can even eventually be dripping from as far down as the oilpain draining bolt, making you think stuff like rear main seals etc. The engineblock of the 4.0 is slightly tilted backwards, making that area end up with oil from way other places.
Keep that in mind.
Not seeing an oil leak waarant more investigation, since there is the possibility for leaking 'inside', like into cooling system, which means far more trouble that the regular lekaing sites like valve cover, oil adaptor filer housing etc.

A good start to find or locate leaks: clean your engine bay with decreaser or the likes (protect your electrical connections) and start observing where leaks occur. Go from there.

Ye Ol' Cherokee

Valuable info here, OP.

My cardboard idea, i should have clarified, was simply to see IF you have a leak. The location of the oil drip will not indicate where it is coming from, like this posters said, the block is tilted back a bit, so thinks leak more in the rear even if they are not leaking there.

What you can do, is if there are drips on the cardboard, you know where to look when you climb under, and you may be able to follow the leak up to its source, maybe

nickengels

i power washed that grime and grease off the block and she was all clean. Heres what i found- I drove it to work and back and let it sit for about an hour and a half after i got home. I just went to check the oil level and see if there was any residue on the area I power washed. The oil level checked fine surprisingly enough. But there was clearly a drip line that looked to be from where the block meets the head. if it was water it would have evaporated, so im pretty confident to say its oil.

I posted earlier that it just had a coolant flush and i was right there when the mechanic did it. Ive known the guy a long time. No oil in the coolant but when i am not running the heat the temp rises above 210 to the 220 ish range. Pretty positive thats not normal running temp.

Adding all of this up, could a bad head gasket be the culprit? Or worst case scenario perhaps the infamous cracked head will plague my XJ as well.

01SiennaXJ

I've heard in several cases that a blown head gasket was causing the vehicle to run hot. If you can see oil leaking from the head gasket its most likely bad, but I'd start with a compression test first to see where you're at.

If you do decide to replace the head gasket, make sure you inspect the head for a crack while you have it off. A lot of the 2000-2001 heads crack, but not all of them do.

nickengels

I've been watching elsewhere to see where there may also be a leak. My pops is F & I at Chrysler dealer so I had it in this morning. There was residue on the side of the block again and oil which appeared to be coming from the rear main seal area. And a little bit of blowback on the tranny pan from driving. We put the dye in it and tomorrow morning it's goin back and puttin the UV light on it to see what the scoop is.