Intake Manifold Build up questions

So i bought an 88XJ with a 4.0 a little over a month ago. After lots of other engine issues i found a donor motor out of an 89 Commanche, that i was able to start and drive before i purchased it, and began the process of cleaning it up to swap into my 88. pulled the intake manifold to find very thick and sludgey black oil buildup. I have read that it could be the CCV, EGR, or valve seats going. yippie!! So besides buying a new valve cover, EGR, or getting the head re worked what are my options?? Mostly what i have been told thus far is watch the dipstick level, keep it topped off, and forget that it even happened. There has to be something else to it that im missing.

Clean it up as best you can. Put it back together and drive it.

As far as the head, You will probably want to repalce the head gasket and such anyways. A good local machine shop should be able to check it over for a minimal cost, and offer advice on if/what anything needs to be done.

Complete gasket set at carquest PN: HS5713
Head bolts PN: GS33414 (These are technically for a later model 4.0L, but are the same size, just 12-pt heads)

Johnnie Walker said:

Clean it up as best you can. Put it back together and drive it.

As far as the head, You will probably want to repalce the head gasket and such anyways. A good local machine shop should be able to check it over for a minimal cost, and offer advice on if/what anything needs to be done.

Complete gasket set at carquest PN: HS5713
Head bolts PN: GS33414 (These are technically for a later model 4.0L, but are the same size, just 12-pt heads)

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I already have the new gaskets and head bolts. my plan was to replace all the gaskets and give it a nice once over before i drop it in. I was planning on setting the head on a piece of glass to check it and "hope" that it didnt need maching seeing everything is closed until tuesday. its probably not a bad idea to get the head cleaned up and looked at by a "proffesional" though. haha.

I had quite the issue tracking down the head bolts but eventually found some on rock auto. for a bit i thought i was the only person that replaced head bolts seeing everyone i contacted said they didnt have any. Even jeep told me sorry. haha.

These heads are common for leaking valves. What my friend has done is set the head upside down, and use some seafoam or something of the sort and pour a little bit in the chamber and see if they leak. As far as the intake, you should be able to clean that decently. Make sure to also use seafoam or Berryman's B-12 through your intake when you put it back together.

"I was planning on setting the head on a piece of glass to check it and "hope"".

Instead: Set a piece of glass on the head.

Not sure how you do that, perhaps just a simple 'head' thing, lol. Perhaps you are thinking of creating a "TRUE TABLE" Surface in which to slide around a feeler-gauge!?! Instead:

Flip head upside down so that the head's engine side gasket surfaces are facing upright, and level out the entire head with a bubble level, etc., using wedges, nuts, bolts, crushed beer cans, whatever. LEVEL is important.

Then coat the machined surfaces with light oil, i.e., spray, and then place the sheet of glass on that surface in which to eyeball through the glass the overall complete continuity of the oil's spread, between the metal, and the glass.

Evenness, i.e., no gaps, complete spread of oil is what you are watching for. Any departure of oil, or unevenness of that sandwiched layer of oil is to suspect a warped head, etc. Play with it. Place a finger to lightly touch the glass, and occasionally press with medium pressure, etc., all around, to see, watch for differences. Make a determination.

I have used the technique of very carefully hand filing down 'heads', in which to mimic actual machine planning of the head in a shop. Now time can be money, so I usually take a 'slightly-off' mating surface to be machined most evenly, to a shop. If no shop around, I use glass. If no glass, lol. No money, but plenty of time.., well it can take several hours to plane down a head using the oil, glass, file method. With this technique: Remember: "Less is More".

Just wanted to perhaps clarify the conceptional use "quoted" as per the the glass/head 'mating' to determine head surface level. Lastly go with Johnnie Walker's advice at this point.

jdjohnson said:

I already have the new gaskets and head bolts. my plan was to replace all the gaskets and give it a nice once over before i drop it in. I was planning on setting the head on a piece of glass to check it and "hope" that it didnt need maching seeing everything is closed until tuesday. its probably not a bad idea to get the head cleaned up and looked at by a "proffesional" though. haha.

I had quite the issue tracking down the head bolts but eventually found some on rock auto. for a bit i thought i was the only person that replaced head bolts seeing everyone i contacted said they didnt have any. Even jeep told me sorry. haha.

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Alaskan89XJ said:

"I was planning on setting the head on a piece of glass to check it and "hope"".

Instead: Set a piece of glass on the head.

Not sure how you do that, perhaps just a simple 'head' thing, lol. Perhaps you are thinking of creating a "TRUE TABLE" Surface in which to slide around a feeler-gauge!?! Instead:

Flip head upside down so that the head's engine side gasket surfaces are facing upright, and level out the entire head with a bubble level, etc., using wedges, nuts, bolts, crushed beer cans, whatever. LEVEL is important.

Then coat the machined surfaces with light oil, i.e., spray, and then place the sheet of glass on that surface in which to eyeball through the glass the overall complete continuity of the oil's spread, between the metal, and the glass.

Evenness, i.e., no gaps, complete spread of oil is what you are watching for. Any departure of oil, or unevenness of that sandwiched layer of oil is to suspect a warped head, etc. Play with it. Place a finger to lightly touch the glass, and occasionally press with medium pressure, etc., all around, to see, watch for differences. Make a determination.

I have used the technique of very carefully hand filing down 'heads', in which to mimic actual machine planning of the head in a shop. Now time can be money, so I usually take a 'slightly-off' mating surface to be machined most evenly, to a shop. If no shop around, I use glass. If no glass, lol. No money, but plenty of time.., well it can take several hours to plane down a head using the oil, glass, file method. With this technique: Remember: "Less is More".

Just wanted to perhaps clarify the conceptional use "quoted" as per the the glass/head 'mating' to determine head surface level. Lastly go with Johnnie Walker's advice at this point.

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Come on Alaska... Did you even read my post? So i typed wrong and said put the head on the glass instead of glass on head. Common sense has to apply somewhere on here. I even stated that i hope that i do not find anything that needs to be machined because they are all closed until tuesday. To me that says that i would use a cheap and easy way to look it over and see if anything is totally fubar and needs to be looked at by a proffesional. I was also implying that i am not a proffesional machinist. Apparently im not an english teacher either. lol.

How many miles on that 25 year old engine? Was there oil in the air cleaner box? Did you do a compression test?

You have the typical CCV issue. Valve seals put oil in the combustion chamber when they're bad, not the intake.

Make sure the tube from the intake manifold to rear of valve cover is clear, that it seals well into the grommet, and that the grommet seals well into the cover. The complete assembly just described can be purchased at Napa for about $12. See post 22 for part number.

Go to the link below and read/perform post 25. It specifically addresses the issue you describe.

http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

The most common reason for excessive blow-by is worn rings. While you have the head off, you may as well replace the rings. Do a light hone to get a pattern on the cylinder bores to help seat the new rings. Use a ridge reamer to get rid of the high area at the top of the cylinders.

I would agree on the honing and new rings as long as the existing rings haven't worn down the cylinders too much. You could end up breaking a new ring.

Finally had the time to get the head off and found this.







Thats alot more crap then i was expecting. I had to chip it out of the rockers to get the bolts out. Same for the head bolts so i could get a socket on them. what a mess. Almost seems like its had a few bottles of stop leak ran through it.

Hypoid said:

How many miles on that 25 year old engine? Was there oil in the air cleaner box? Did you do a compression test?

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This donor motor supposedly only had 130k. The airbox was clean and i did not perform a compression test as it was running fine before i helped pull it.

winterbeater said:

The most common reason for excessive blow-by is worn rings. While you have the head off, you may as well replace the rings. Do a light hone to get a pattern on the cylinder bores to help seat the new rings. Use a ridge reamer to get rid of the high area at the top of the cylinders.

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old_man said:

I would agree on the honing and new rings as long as the existing rings haven't worn down the cylinders too much. You could end up breaking a new ring.

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The cylinder walls look spotless so thats a good sign atleast. last motor i pulled the head on had huge scoring marks from bad rings. I have not pulled the oil pan yet so when i get it all apart i will decide if i want to go for a full rebuild or just refresh the top end.

Seems that engine was a victim of too few oil changes........

I've seen worse and they came back to life.