02jgcwj

Well here's the scoop...
2002 jeep grand cherokee 4.0 that had the good old 0331 head.
I limped it for about 8 months keeping an eye on ething. As soon as the vehical temp went above what it normally does here in las vegas I ordered a new head from clearwater. I just finished installing it this weekend and when I went to start it for the 1st time it acted like it wasn't running on all cylinders/timing was off. I redid my TDC and looked into the cam position sensor. The sensor was off a little and it made my jeep run for a little while but again was REALLY rough. I noticed alot of water and oil coming out the tail pipe so I shut it off, checked the oil and it has just started to mix. It's still yellow cause its fresh oil but how does this happen? I changed ething and it went smooth except for the exhaust/intake manifold. It only ran fo about 5 minutes.. is there a chance the head and or block is done for?

dave1123

It's possible the block deck is distorted from running it with a blown gasket. You should have check it's condition before installing the new head. The only thing to do now is take it apart and check the deck surface for dips or melted spots. The block can be milled, but it has to come totally apart to do it.

02jgcwj

It didn't have a blown head gasket b4. It had the stupid 0331 casting head that cracks between the 3rd and 4th cylinder. I bought a new 1 b4 it really went.. I also replaced the cam, lifters, pushrods and rockers while I had it apart. I did ething by the book but for some reason the gasket didn't hold. Compression test says it's leaking on the 2nd or between the 2nd and 3rd cylinders. I used the better felpro gasket to.. thinking I might try a cometic gasket this time and avoid the fiber all together.

02jgcwj

Oh and it only tan for maybe 3 minutes after I did the head. Didn't even get warm so I'm hoping ething is still ok.

dave1123

Sorry, I didn't mean to upset you. You stated that you "limped it for 8 months" so I assumed it was leaking compression then. My 2000 4.0 had the same problem in that it was leaking coolant out the tailpipe and making steam, but not contaminating the oil. It apparently cracked into an exhaust port but not into the valve area. I used a Victor-Heinz multi-layered steel gasket and new bolts. Now it's steaming just a little, but using a lot of oil with no noticeable leaks. I'm chasing a misfire code on #4 that seems carbon related. Seafoam took care of it, but I'm wondering how good their valve stem seals are. It's not blowby because the crankcase vents are dry. I don't think it's the rear main because after idling for 3 hours, there's only a quarter-sized oil spot on the ground under it. There's no visible oil smoke in the exhaust yet, but I'm using about 1 qt in 300 miles.

OH!!!....WAIT!!! You bought a Clearwater head, right? Those are drilled for a rear temp sensor as well and have a steel pipe plug in the hole. Mine wasn't tight and was painted over. It was fine for 2 days, then started leaking coolant around the intake manifold near #4 and #5 cylinder. I Freaked Out!! My mechanic found it and we fixed it. I even sent Odessa an e-mail *****ing them out about it.

Check your head bolt torque. They may have "settled in" meaning they are loose. Fel-Pro also makes a Severe Duty gasket that supposedly seals better if you have to go that route.

I seem to be rambling.

02jgcwj

I wasn't upset.. I've done plenty of head jobs and this is the 1st 1 where it leaked after. I was super careful setting the head on the block and spent 4hrs cleaning the deck so it was perfect for the gasket. Now that u mentioned the plug in the head it makes sense. I saw it but didn't think to check it. I used the felpro severe duty gasket as well cause it was the only 1 in town. I had to go to 3 different places to get all the parts together to do it cause No1 had anything. I think this time I may try the Victor but not sure... I have a warranty on the felpro and other then fiber it looked like a good gasket. I've always used copper or metal gaskets on e car I've worked on. It always made me feel better knowing that they're more stout. Thanks for the reply man.. hopefully this weekend I'll have it done again and can go mountain biking finally.

dave1123

I buy 99% of my parts from rockauto.com and with over 30 orders, they have yet to give me the wrong or a bad part. The best part about them is they give you options on which parts to buy.

The reason I suggested checking the head bolt torque is because a fiber gasket has a tendency to "relax". I've used fiber gaskets on Chevy small-blocks for years and never had them relax on me because I always torque them up, then go have a couple of beers, then check them again. They'll drop down 10 to 15 lb/ft. I torque them again and they usually don't change again on a hot torque.

02jgcwj

Well at the moment I'm working on a solar job and drive 100+ miles a day and I'm driving the caddy through 7 miles of desert and I can't really wait for parts to ship. I did look up all the parts and they would make it on Monday but I need it done this weekend. The old lady wants her cadillac back haha.

dave1123

I hear you there. There isn't anything worse than a woman with "clipped wings!"

02jgcwj

Well pulled the head again, re did ething and found out my pivots and rockers were toast all of a sudden. I ordered new ones, installed them and it started running lime it should but with a little miss. Drove down to my local union meeting and about half way there it started getting worse and the rockers started clacking again. I'm at a loss as of now.. can't figure out what the problem is. I don't think it takes this long for the lifters to pump up or get all the air out of them. Anybody have a good place to start checking?

dave1123

IDK man, if the oil pressure is good and the lifters are getting oil to the rockers, I haven't a clue. I usually "prime" my lifters by submerging them in oil and working the plunger, but nothing says you HAVE to, it only takes about 2 to 3 minutes for them to quiet if you don't. You said the pushrods are new, so they shouldn't be plugged. I'm assuming the rocker pivots didn't loosen up, right?

I once had an older mechanic (older than me) tell me the reason the jeep 4.0 lifters always click at idle. He says the oil supply ports to the lifters are small and if the bearings are worn AT ALL, not enough oil gets to the lifters to keep the lash closed at idle, but they quiet at about 1000 rpm. When I did my head, I put new Sealed Power lifters in it and they were quiet for a while, but returned to the 4.0 rattle after about 1000 miles. I started to brag about Sealed Power only to eat my words later.

02jgcwj

Well I figured out my rough idle. After changing the map sensor and doing the timing yet again I checked the resistance on the upstream 02s. They tested fine but I noticed that I get my rough running after its warmed to operating temp. I have no check engine lights but I unplugged the 02s 1 at a time and when I pulled the 4 through 6 it started running 50x better. I drove it and power is back and a normal idle. Waiting on new ones to get to napa and changing those. As for the rocker tick.. it actually calmed down with the 02s unplugged but I'm going to pull the valve cover 1 more time and re torque since it's had a few heat cycles.

02jgcwj

Oh and I soaked everything over night in oil b4 installing them. I have 20ish#s of pressure at idl, fuel is about 47-48 and I forget what vac was but it was way good. That you so much for your patience and you help.

dave1123

Chrysler says 10 psi is safe, but I'd be kinda scared if that's all I had. As long as it comes up to around 40 psi at about 1500 or better, I'd be happy. Mine runs about 45-50 on cold start, 40 at idle hot, and about 50 at 60 mph. That's with 190K miles on it and after a cracked head.