New jeep, new head problems?
 

Hey guys. Just bought a 2000 xj with 230k miles as a project truck. The jeep will need a lot of attention, but there's one problem that has become the first priority. Antifreeze in the oil!

I've done my research, have a list of symptoms, and did a compression test. Learned afterwards that holding my throttle open while testing helps? For now, I'm looking for input from all of you. So here's what I've got going for me so far:

1) White foam underneath oil cap
https://cimg1.ibsrv.net/gimg/www.che...ac3c7121b3.jpg



2) Steam coming out of valve cover, along with bubbling and fizzling

3)No sludge/milkshake on my dipstick. There are a few small bubbles at the top of the oil reading though


4)No exhaust bubbles in radiator while the jeep is running



Other thinks worth mentioning:
-Does not overheat at idle, elec. fan kicks on around 220
-Exhaust smells sweet, but isn't white
-Warms up faster than my old xj did
-Vehicle has a lifter tick


Compression test results:


DRY:
Cyl. 1-----135
Cyl. 2-----160

Cyl. 3-----130

Cyl. 4-----175

Cyl. 5-----165

Cyl. 6-----170


WET:
Cyl. 1-----175

Cyl. 2-----180

Cyl. 3-----155

Cyl. 4-----195

Cyl. 5-----190

Cyl. 6-----195


I might have time on Sunday to make up a tool to compress each cylinder individually and check for exhaust in the radiator again. For now, the compression test isn't showing me too much. Any input?

Search for "0331 head" and do a little reading, looks like that could be your issue.

Did you drain the oil? What did that look like? Has the jeep been sitting? Maybe it's just a little condensation if you're lucky????

I'm an optimist. :icon_smile:

Yank the whole engine out and rebuild everything, except the head.

Use it for a doorstop or a boat anchor and buy a brand new aftermarket replacement. The original head is not restorable. The used 0331 heads are no good either.

If you're going to keep it.

I'm afraid he may very well be correct from the way it sounds and the mileage on it for that year/head combo. The head is good for nothing but its weight for scrap, I would imagine that the block will be fine for a rebuild.

Thanks guys. I've been looking up info on the heads on my year and can't say I'm happy with what I found. With this many miles on the vehicle, I was considering buckling down and learning to rebuild it anyways. Hopefully the block will be alright. The jeep looks like it's been maintained pretty well. If nothing else, the jeep is worth keeping for the body, it's in great shape.

The oil I drained from the pan didn't show any signs of coolant and had no metal shavings. The exhaust also isn't blowing white smoke. So maybe if I'm lucky it will just be condensation.

Thanks again, love this site!

Hold on. Not all 0331 heads are junk. 02-04 WJ (grand cherokee) and 02-06 TJ (wranglers) have TUPY 0331 heads, they are revised and improved designed heads. Direct bolt in on 2000 and above blocks.

Much cheaper than buying brand new heads.

That's what I did.

Now if I were able to find one of the TUPY heads at a junkyard, would I have to look into bringing it to a machine shop? Could my rockers and springs be switched between a TUPY and non-TUPY head?

yes I reused my xj springs and rockers on the WJ head.

I didn't take my head to the machine shop because I checked the flatness with a granite surface table and feeler gauges (I work at a machine shop myself) and it was still straight (I got lucky and the head had only 109k miles on it). I simply took a stone and cleaned the mating surfaces and replaced the valve stem seals and did some general cleaning.

Thanks for the tip. This will save me a whoooole lot of bs if it turns out that the head really is cracked.

I should have qualified my earlier post by saying 0331 XJ heads are junk. XJ production ended in 2001.

Non TUPY heads.

If your used replacement has a burned seat you'll be pulling the head again. Better to just fork over the bucks now to have it reconditioned.

Why no mention of oil pressure, have you checked with a mechanical gauge?

The oil pressure was normal on the dash, so it didn't cross my mind to mention it here on the forum. Do you mean I should check the oil pressure with another device besides the dash?

Out of curiosity, how is oil pressure related to the issue?

yes. And factory dash gauges aren't that accurate lol.

Take out the oil pressure sender, screw in the mechanical gauge and verify pressure

Gotcha :thumbsup: I'd rather do simple tests before tearing this jeep apart.

I'll see if I can't get ahold of an oil pressure gauge once I'm paid. I'm a little tight on cash after buying the jeep! I'll keep you guys updated.