Getting ready to change out a cracked 0331

Hi All,

I know there are many posts about the 0331 head issues. I'm not losing noticeable amounts of coolant, but I'm seeing a upward trend in the amount of potassium in my oil. I looked down the oil filter cap and see the tell tale crack. The upward trend started about 2 years ago when my thermostat failed. The engine runs fine and does not smoke.

I've pulled heads on Mercedes diesels before, but I haven't worked on this motor other than routine maintenance because its been so reliable, so I have some "newbie" questions.

1. I don't want to spend money on an engine on its way out, so I did a compression test. I'm not sure how to count 3 revolutions from the drivers seat? I listened to the starter and let it engage for 8 cycles. Results were 120,110,110,112,112,120 @ 6,500 ft. Adjusted for elevation 145,133,133,136,136,145. These seem like pretty good numbers for a bottom end with 314,000 miles.

2. Spark plug #1 had carbon on it, unlike any of the others which all looked the same. Any ideas why? #1 injector was replaced about 160-200K miles ago because of a misfire, prior to realizing it was a valve seat issue affecting multiple cylinders. Anything I can do or check for the carbon?

2. I removed the valve cover to look inside. I was able to hand turn all the push rods except for 2. Is this related to position of the cam and valves or should they all turn freely no matter what the engine position? Do I have a problem? Should I change the lifters? I was surprised that the valve cover gasket, which has 160,000 miles still does not leak.

3. Is there any advantage to using the dealer upper gasket set compared to the Fel Pro gasket set?

4. Where is the best place to buy exhaust manifold bolts and studs?

5. Are pipe sealant, Copper RTV, or Loctite 592 all appropriate for the #11 head bolt?

6. Is it recommended to put anything on the intake/exhaust gasket or install it dry?

7. Why does the gasket set include a throttle body gasket? Is that in case you want to clean the throttle body and intake manifold while its off?

8. I ended up removing the upper radiator hose to get to the valve cover off and then had to put it on at an angle to get around the rear wiring harness etc. Will it be similar with the head?

Thanks!

Re: Getting read to change out a cracked 0331

md21722 said:

1.These seem like pretty good numbers for a bottom end with 314,000 miles.

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314,000 miles? Is that correct? If so that is good compression.

Any ideas why? #1 injector was replaced about 160-200K miles ago because of a misfire, prior to realizing it was a valve seat issue affecting multiple cylinders. Anything I can do or check for the carbon?

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Histor on the #1 injector? uses, new, same injector as the rest?

I was able to hand turn all the push rods except for 2. Is this related to position of the cam and valves or should they all turn freely no matter what the engine position? Do I have a problem? Should I change the lifters?

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The pushrods won't turn if they are on a love that is significantly in the open position. Sounds like #2 is opening so it is under pressure and you can't turn it. I wouldn't replace the lifters unless there is a problem. You could take the out one at a time and inspect them. Just make sure you put them back in the same hole they came out of.

3. Is there any advantage to using the dealer upper gasket set compared to the Fel Pro gasket set?

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Nope

4. Where is the best place to buy exhaust manifold bolts and studs?

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Dealer or work up your own solution from some place like mcmaster car.

5. Are pipe sealant, Copper RTV, or Loctite 592 all appropriate for the #11 head bolt?

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Loctite 592 would be the best bet but the others will suffice.

6. Is it recommended to put anything on the intake/exhaust gasket or install it dry? [/quote I always use a light coat of copper RTV.

7. Why does the gasket set include a throttle body gasket? Is that in case you want to clean the throttle body and intake manifold while its off?

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Usually you are taking everything apart, that is why it is included.

8. I ended up removing the upper radiator hose to get to the valve cover off and then had to put it on at an angle to get around the rear wiring harness etc. Will it be similar with the head?

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The valve cover can be removed with out messing with the tstat housing or the hose. You just need to angle the cover correctly. The t-stat housing will need to come off for the head any how.

A few tips. Assemble the head and manifolds out side the vehicle. Then drop it all in with and engine hoist. Much easier than trying to be a contortionist. Don't clean the gasket surfaces with one of those 3m abrasive scotch lock discs like some people love. It will create an uneven surface.

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Re: Getting read to change out a cracked 0331

Thanks for the response. No typo - it really has 314,000 miles. The head was reworked at 160,000 miles to cure a misfire caused by low compression. It was determined that the valves weren't sealing properly. It was never determined why but I found a few cases where people had similar problems and it was attributed to stiffer valve springs due to emissions on later XJ's. The #1 injector was replaced prior to the head work along with the coil pack and CPS as it was believed these could be causing the misfire. All the other injectors are original. Maybe I need to run some injector cleaner through it and replace that injector if it doesn't clear up? Doesn't appear to be causing any drivability/power/smoking issues.

Is there any issue using Grade 8 bolts for the intake/exhaust manifolds?

I'd be inclined to pull the manifolds with the head but I have the mini-cats and it looks easier to remove the manifold bolts than deal with the exhaust bolts next to the oil pan. They look liked they are rusted solid?

Re: Getting read to change out a cracked 0331

md21722 said:

It was never determined why but I found a few cases where people had similar problems and it was attributed to stiffer valve springs due to emissions on later XJ's.

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Not likely. They aren't that stiff. An increase of 10/20 seat load is insignificant.

The #1 injector was replaced prior to the head work along with the coil pack and CPS as it was believed these could be causing the misfire. All the other injectors are original.

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Swap the #1 injector with another injector and see if the misfires follows it.

Re: Getting read to change out a cracked 0331

The misfire went away when the head was done and the plugs looked fine.

Sometime after the engine got hot about 2 years ago and ending a couple of months ago, I'd get grayish smoke (seen in the rear view mirror at night) under high load, like climbing Monument Hill elevation 7200-7300 in 3rd at 80MPH. I changed the plugs recently and noticed a couple of them had carbon on them. With the new plugs, only #1 has carbon. I'm not sure why the smoking started or stopped. For all I know it was gas, etc. I didn't attempt any repair except trying to use Diamond Shamrock gas that the Jeep seems to prefer above all others.

I think I'll swap fuel injectors 1 and 2 and see if the carbon moves... if that's the case, is any additional troubleshooting required? Would the solution be to change out the injector that causes the canon?

Re: Getting read to change out a cracked 0331

Grey/blue smoke = oil
Black smoke = gas
white smoke = coolant

Re: Getting read to change out a cracked 0331

I have a question about the manifold bolts BELOW the intake- the ones you cannot see by looking down at the top of the engine. Is there a trick to being able to see these/get a socket on them? If I look from under the engine I can see one or two. This is a 2001 with the mini-cats.

It looks like all the bolts and stud nuts are 9/16". I'm assuming a 3/8" drive 9/16" socket, universal, suitable long extension, and a 1/2" drive long handle ratchet will be able to do the job?

Also, I figure its a good idea to clean out the head bolt holes in the block with some brake cleaner and a tap. What size tap should I get? I don't have a complete set so I'd like to get it ahead of time.

Thanks!

Re: Getting read to change out a cracked 0331

My Jeep is a 2000 with the mini-cats. When I swapped the head I actually had to lay on top of the valve cover and had my buddy under the Jeep with a flash light directing me where to go. I actually found it easier with a 9/16" wrench instead of a ratchet and socket. A swivel extension may make it easier with a ratchet. I recommend spraying all of the manifold bolts with PB Blaster or Kroil ahead of time. My buddy broke an exhaust manifold bolt on his '98 ZJ with the 5.2 V8 and it was a major pain to get it out. The 4.0 bolts came right out, but its never a bad idea to spray them first.

Re: Getting read to change out a cracked 0331

Thanks. I've already started with the kroil, on the stuff I could see. I'm having trouble visualizing using a wrench with those mini-cats in there, but I'll take your word.

When removing the power steering pump, it almost looks easier to remove the entire water pump, etc.? I am thinking of removing all fans, shrouds etc in the front of the engine, air box, etc. Sometimes its quicker to remove parts then try to work around them.

Any tricks on the rear head bolt with the ground wire that's directly below the wiring harness? I'm tempted to disconnect all the connectors on the passenger side and move that entire part of the wiring harness out of the way.

Re: Getting read to change out a cracked 0331

I went in from the front, under the manifolds... then again I didn't have the ps pump on there. I could easily fit my whole arm under there with a socket wrench, iifc.

Re: Getting read to change out a cracked 0331

I can't recall how I accessed them but I did remove the original manifold on my 2000 with it in the bay. Try to use a long extension and go from the top, but under the intake manifold.

Re: Re: Getting read to change out a cracked 0331

md21722 said:

I have a question about the manifold bolts BELOW the intake- the ones you cannot see by looking down at the top of the engine. Is there a trick to being able to see these/get a socket on them? If I look from under the engine I can see one or two. This is a 2001 with the mini-cats.

It looks like all the bolts and stud nuts are 9/16". I'm assuming a 3/8" drive 9/16" socket, universal, suitable long extension, and a 1/2" drive long handle ratchet will be able to do the job?

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If you pull the PS pump and stock air cleaner, it becomes really easy to get a hand under / behind the manifold and put the socket onto the bolts. Still need the extension to turn and tighten though.

Re: Getting read to change out a cracked 0331

First time I did the intake/exhaust on my 00 (was doing freeze plugs) I did everything from the top with someone spotting. Putting it in is worse then taking it out. Also it was worth it for me to go out and buy a 9/16 ratcheting wrench for this (especially that back bolt). Socket has a hard time fitting in some of those spots. I also had to use a couple extensions to use a ratchet on the bottom. Didn't need a swivel. Right now I am mid engine swap and it was much easier to get to the bolts by removing the header, radiator, ps pump, and air box. Wasn't really all that much more time/work but I am so used to having to swap radiators in these that it was no work at all. If you need a good picture of all the bottom bolts I can snap a shot of the my motor on the lift.

Re: Getting read to change out a cracked 0331

Also don't know if you are getting a new head or a used one but if you are going used look for a head with the TUPY casting on it. I know it came in late 02 till 04 wjs. Different casting which is not prone to cracking. It's easy to check. It actually says TUPY right when you open the oil filler and look in with a flashlight. If you are going new with a Clearwater or other brand disregard this lol. I did some research after finding out my 0331 head cracked at 260k (she had a good run).

Re: Getting read to change out a cracked 0331

I believe the head bolt threads are 1/2"-13? Can anyone confirm?

Re: Getting read to change out a cracked 0331

How do you torque the rear head bolt with the ground strap? There isn't enough clearance for a 1/2" drive drive 1/2" 12-point socket with a 1/2" drive torque wrench.

It looks like there would be enough room if I used a 3/8" drive socket and a 3/8" drive torque wrench, but my 3/8" torque wrench only does 10-80 ft lb...

Is the best way to get a 3/8" drive torque wrench that does 150 ft lb?

Re: Getting read to change out a cracked 0331

I seem to remember using a beam style torque wrench to tighten that one-- the one that uses deflection to show the torque. I think I guestimated the torque during installation and re-visited it with a beam style wrench (once I dug mine out of the "I never need this again" pile) after everything had heat cycled a few times.

Re: Getting read to change out a cracked 0331

I'll keep that in mind.

It looks like the best I can do without buying new tools is use a 3/8" drive deep well socket, universal, and a 1/2"F x 3/8"M adapter at around a 15 degree angle. I think once you go past 15 degree torque computations are needed.

Would prefer if the torque was something like 45 ft lbs and then 90 degrees!

Re: Getting read to change out a cracked 0331

I used a 12 point short socket. Half off the torque wrench but just enough to not slip off under torque. Its a pain but i have done it many times this way.

Re: Getting read to change out a cracked 0331

I found that my 1/2" socket would not fit over the bolt, but thanks to a guy over at cherokeeforum I tried a 13mm instead and that fits. Thanks!