Replace a 4.0 cracked head after driving 800+ miles with coolant in oil?

Crud. I tried. But really, why cant I simply attach something here directly???

JohnEP
1) You're not a club member, you're a registered guest.
2) NAXJA is not a hosting service. We do not want to host attachments of everything under the sun.
 
Me being me, I'd pull a couple of rods & a couple of mains for visual check - bearings that are wiped out due to contamination are usually obvious.

If they're wiped out, recommend replacing all of them (including the camshaft bearings. I know, I know...)

However, it's possible that you haven't wiped out your bearings. But, the first commandment is, "Thous Shalt NEVER Assume, for to do so makes an ASS of U."

What's the harm of the wait-and-see approach? After the head job is done, I plan to use it as my daily driver (locally only) for the next 1000 miles. I figure if the oil pressure holds, and it still sounds good running, why go looking? Could I ruin something else that would not need to be replaced anyways? Maybe I'm being nieve... Next summer, I plan to use the Jeep to tow my 3000 lb boat up North. If this kind of work "stresses the bearings more," then I'd hate to be stranded up there, as my engine bearings suddenly fail while pulling the boat out (up the ramp) to go home...

Update: got the head torqued on. WARNING: do not trust "rental tools" torque wrenches (from Autozone, etc). I set it at 22 lbs for my first bolt: the clicker never clicked. I stopped at about 25lbs b/c I knew something was wrong. Tested it on my lug nuts: worked perfectly while in "reverse" (it clicked really easy at 22), but in "forward" I had to CRANK it to get a click at that same 22 setting. Called the store and exchanged it.

Despite Talyn's assurance that no oil is needed on the rings, I am so tempted to put a bit of Rotella T on them, with the ?mistaken? idea that it will protect them (break them in to the cylider wall) against any crud I might have left down in that gap. Of course, I have zero understanding of how the upper rings are lubricated in the first place.

As for this forum not hosting pics for guests: I better understand why. I did not see that rule when I was following your site's instructions on how to post pics. No big deal. Thanks again.

Your advice appreciated,
JohnEP
 
Bad news... while cleaning the rocker pivots, they look shot. How telling IS this about the state of my lower bearings? Maybe 5-90 has a good point: open the bottom and see. Oh well, I'm already "all in." I'll finish the top first, right after I order some new rockers and pivots.

Lets see if I can get my google account to work for pics: pic of rocker pivot:
https://plus.google.com/photos/109202864701715797960/albums/5848621545458266577

JohnEP
 
What's the harm of the wait-and-see approach? After the head job is done, I plan to use it as my daily driver (locally only) for the next 1000 miles. I figure if the oil pressure holds, and it still sounds good running, why go looking? Could I ruin something else that would not need to be replaced anyways? Maybe I'm being nieve... Next summer, I plan to use the Jeep to tow my 3000 lb boat up North. If this kind of work "stresses the bearings more," then I'd hate to be stranded up there, as my engine bearings suddenly fail while pulling the boat out (up the ramp) to go home...

Update: got the head torqued on. WARNING: do not trust "rental tools" torque wrenches (from Autozone, etc). I set it at 22 lbs for my first bolt: the clicker never clicked. I stopped at about 25lbs b/c I knew something was wrong. Tested it on my lug nuts: worked perfectly while in "reverse" (it clicked really easy at 22), but in "forward" I had to CRANK it to get a click at that same 22 setting. Called the store and exchanged it.

Despite Talyn's assurance that no oil is needed on the rings, I am so tempted to put a bit of Rotella T on them, with the ?mistaken? idea that it will protect them (break them in to the cylider wall) against any crud I might have left down in that gap. Of course, I have zero understanding of how the upper rings are lubricated in the first place.

As for this forum not hosting pics for guests: I better understand why. I did not see that rule when I was following your site's instructions on how to post pics. No big deal. Thanks again.

Your advice appreciated,
JohnEP

You really only need to oil the piston rings if you're doing a wet/dry comparo on a compression test. Else, why bother? Net effect - you'll contaminate your catalytic converter matrix.

Wait and see if you like, I'm just paranoid. Given that engine oil tends to hit 220-250*F at times in operation - which exceeds the boiling point of entrained water - you can end up with gas (steam) in the oil film on your bearings. The working stresses will make them explode rather violently - just very small ("cavitation," or a relative thereof.)

These gas pockets blowing out often taken small pits of metal with them, and bearing metal is soft.

By now, you get the idea. Some small pitting of the bearings isn't a huge problem, but it's also possible that they can get wiped out in a big hurry!
 
Oh... that is really bad. I really would stop working on the top end and pull the oil pan and look at the main and rod bearings.

Hmmm... Sounds like a LOT of work... I'd rather go with THIS guy's advice:

If your oil pressure is good I would run it with a TUPY head. Do multiple oil changes to get rid of the coolant.

Heh heh. Seriously though, I do appreciate your advice. I'm already so far invested into this, I think I'm going to put faith in my prior oil pressure readings, and just put the head back together. Maybe I'll just put the old rockers and old valve cover gasket on it for a while. If the lower engine starts acting up, at the very least, I could drive it to the junkyard with pride. If lower sounds good for 1000 miles, then maybe add the new rockers and valve cover gasket. Does this sound reasonable (will I really hurt anything running those torn-up rockers (see better pic below))? Or, for an extra $90, I could just put the new rockers on now. Hmmm.... Your thoughts?

Another attempt to insert pics...

A good shot of my 2000 non-TUPY 0331 crack:
IMG_0667a.jpg


Lifting method (OK to call me a wimp for needing 3 guys):
IMG_0678a.jpg


Cleaned block:
IMG_0677a.jpg


I guided it while the other guys lowered it: perfect landing on the gasket.
IMG_0679a.jpg


This last pic shows a more realistic view of the same pivot I photographed before. It is the worst one, but still representative of ALL of them.
IMG_0684a.jpg
 
Does this sound reasonable (will I really hurt anything running those torn-up rockers (see better pic below))?
Yes. They won't exactly glide against the contacting rocker surface and send more metal through the engine.
Lifting method (OK to call me a wimp for needing 3 guys):
Nope, that head is heavy. It isn't an aluminum V8 head. However since you had help I would have bolted the intake and exhaust on out side of the engine bay then dropped it all in. I usually do that and use an engine lift to put it in and out.
 
OK. A friend pulled some nice shiny junk-yard rockers and pivots for me. Some of the junk-yards bridges are twisted though... (see pic with twist below). How to remove the pivots and put them on my old bridges? Also, the junk-yard parts he gave me are all loose in a bag (not matched). Any advice on how to choose which rocker to install on which pivot? Are the diagonal oil grooves on the pivot supposed to criss-cross the grooves on the rocker, or mate them (I'm guessing "mate" for max flow).

IMG_0688a.jpg


since you had help I would have bolted the intake and exhaust on out side of the engine bay then dropped it all in. I usually do that and use an engine lift to put it in and out.

Dang it. That is obviously the best way to do it, both in and out! I DID attempt to remove it that way, but the exhaust bolts were so rusted, that the nuts just spun and demolished the rusted "nut retainers." Do you know a good way to remove or cut those bolts when everything is still installed?? (I'm thinking about posting a total write-up when this is done, for others who attempt it in the future).

I'm not looking forward to re-installing those lower intake/exhaust manifold bolts. Hopefully, it will be easier than it was removing them. Luke; use the force!
 
You can unbend the bridges. The bridges are a bit of a press fit onto the trunnions, but not very much. I don't know of anyway to match them back up, but in this case that shouldn't matter much. Its not like lifters on the cam lobes.

As for getting the exhaust bolts off, if you don't have room for a full sized die grinder you can use a dremel. If you can get a wrench on both end then just break the bolts and replace them.
 
You can unbend the bridges.

That was my first thought as well. I have some recent experience re-bending metal back into shape (using jacks, bars, blocks, levers, gravity, etc.) First stabilize the parts that you don't want to move, then apply force only to the part that you DO want to move. I think I'm up to that task; just need to round-up some tools I lent out (where did all my locking pliers go?).

As for getting the exhaust bolts off, if you don't have room for a full sized die grinder you can use a dremel. If you can get a wrench on both end then just break the bolts and replace them.

I considered these methods myself during the disassembly, and I failed. When all is assembled, you cannot see those exhaust nuts from the top. You CAN see the bolt-heads from the bottom, but it takes 3 or 4 extensions to reach them. No way to see the body of the bolts (the part you'd want to cut with a dremel). So, you'd have to "use the force" to connect on any of these areas. Even so, I wish I had done it YOUR way, rather than "using the force" and perfect-length extensions to find those damn intake/exhaust manifold bolts from the top. Too late for me now anyways; I already have the new naked head torqued on. Just thinking about the next guy...
 
I got her all back together and running. Engine sounds great. After 10 miles on the freeway, then sitting at idle for 20 min, the dash oil pressure settles at 20 PSI. I am optimistic.

THANK YOU ALL for your help. I'll report back on how she holds up.
 
I've got 200+ miles on the odometer now since my "cracked head replacement." At idle, dash gauges still read: 650 RPM; 205 deg F; 20 PSI after driving home from work (9 miles). Getting 16MPG per engine computer.

Do we all agree that my lower bearings are "fine," based on the 20 PSI dash gauge reading alone? Any OTHER 'tests' to do for the lower bearings that do not involve removing the oil pan? Rev and listen?
 
8 miles isn't enough to get the oil up to temp, especially in this weather. Take it for a longer drive, like 30 minutes to get the oil hot then read the oil pressure.

Very true. Got 400+ miles on it now. After my 50 mile drive home today, idle settles at 700 RMP, 205 deg F, 18 PSI (dash readings). Engine computer says about 21 mpg highway at about 70 mph, windy conditions. When I started it this icy morning, I heard a bit of ticking (like usual) at cold idle. After my 50 mile drive home, I heard no ticking at all at "truly hot" idle.
 
My off-topic reply to:
1) You're not a club member, you're a registered guest.
2) NAXJA is not a hosting service. We do not want to host attachments of everything under the sun.

My Feedback (as a non-expert poster): As a "registered guest," I wanted to post my pics relevant to this thread, in order to help myself, and other DIY guys who want to try this after me. Unable to post pics from within this site, I finally signed up for an external service to do so. My then successfully posted pics in this thread are now suddenly gone, because ?I changed a setting in my hosting service?. Right now, your permissions state that I MAY edit my posts (to fix these broken links), but I see no button to do so. I appreciate this forum. I offer this feedback only in case you might find my experience to be useful to help other newbies / non-club-members.

Is there any way for me to be an "honorary club member" for swapping out the head myself, and reporting back? I am planning on a full write-up for the DIY guy. Looking for the best place(s) to host it...
 
My off-topic reply to:


My Feedback (as a non-expert poster): As a "registered guest," I wanted to post my pics relevant to this thread, in order to help myself, and other DIY guys who want to try this after me. Unable to post pics from within this site, I finally signed up for an external service to do so. My then successfully posted pics in this thread are now suddenly gone, because ?I changed a setting in my hosting service?. Right now, your permissions state that I MAY edit my posts (to fix these broken links), but I see no button to do so. I appreciate this forum. I offer this feedback only in case you might find my experience to be useful to help other newbies / non-club-members.

Is there any way for me to be an "honorary club member" for swapping out the head myself, and reporting back? I am planning on a full write-up for the DIY guy. Looking for the best place(s) to host it...

the edit button times out after a while, members get the same thing.

if you want to fix the links PM the moderator of the forum with the updates and ask them to fix it.
 
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