Jeep Cherokee Talk banner

21 - 40 of 47 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter #21
Flip the head over. And see if the valves are all closed.
I Can see a little black, which is carbon from your exhaust between 2 and 3 3 and 4. It might be there, but I would think those other cylinders would low on compression. Try to wiggle the piston in the bore.
This is the underneath of the head the circle things on the second cylinder look darker than the others and on top of cylinder three one of the holes is gunked up. Haven’t found any cracks yet but I think I am just going to take the head to a machine shop and get it magnafluxed to verify. however it is a couple weeks lead time on that test. I sprayed the open part on the inside down with degreaser wiped it off and coated it with fogging oil. Anything else I should do to avoid rust?
228316
 

·
Super Moderator
Joined
·
10,519 Posts
Lay the head down on the rockers, spray cleaner on the #2 cylinder valves and see if the cleaner leaks past the valves. Spray some WD-40 or engine oil in the #2 cylinder in the block and see if it leaks passed the rings. All that black could be from unburned fuel or oil leaking passed the piston rings.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #23
Thanks for the tips I don’t know what I’d do without guys like you on this board and YouTube videos lol.

What would leaking fluids between either of these tests indicate? And what would be the recommended fixes? Could these culprits explain the misfire/bucking/white exhaust issues that I was getting before I took her all apart?
 

·
Super Moderator
Joined
·
10,519 Posts
Well that's what we are trying to figure out.
Both intake and exhaust valves are in the "closed" position in the heads current state. If fluid leaks past them on the bench then it means they are not sealing and will cause compression loss. Meaning that's why your compression was low on that cylinder. Same thing if the piston rings don't seal.
A blown head gasket most commonly fails between two cylinders, affecting the compression in 2 adjacent cylinders. Since you only have low compression on 1 cylinder, I'm trying to determine what is the cause.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #25
Well that's what we are trying to figure out.
Both intake and exhaust valves are in the "closed" position in the heads current state. If fluid leaks past them on the bench then it means they are not sealing and will cause compression loss. Meaning that's why your compression was low on that cylinder. Same thing if the piston rings don't seal.
A blown head gasket most commonly fails between two cylinders, affecting the compression in 2 adjacent cylinders. Since you only have low compression on 1 cylinder, I'm trying to determine what is the cause.
Ahh gotcha I get what your saying about the valve covers in the head I can do that and the ones on cylinder two look suspect.

dumb question but where will the oil leak out if I spray some down on cylinder two? Will I have to take a look from underneath?
 

·
Registered
Joined
·
7,102 Posts
To further paint a picture on what Gluck is describing.........when I replaced mine, it was mostly because cylinder 1 was missing and had no compression. My headgasket appeared to be fine, but I had a bent valve in cyl.1 that wasn't sealing. Whether your valves may be bent or just no longer seating is a question we have yet to find the answer to. Pouring fluid on top of the valves will allow us to see if its seating and sealing or not. If not, fluid will run out of the associated passages for the valve. The exhaust valve will lead to the exhaust manifold holes in the side of the head where the exhaust manifold bolted up. The intake valve will lead to the intake holes where the intake manifold mounts.
 

·
Super Moderator
Joined
·
10,519 Posts
⬆ thanks superman for clarifying perfectly.😁
Also, what you spray into the cylinder will leak down into the oil pan. Which is why I said use oil and not brake cleaner (it will dissolve all the oil on the bearings, very bad). Since taking the head off opens up the engine it also makes an oil change mandatory.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #28
Oh shit this is good to know I should have been more careful. I may or may not have already sprayed the cylinders and block down with degreaser and fogging oil under the advice of my half drunk buddy that was working with me.

I hope I didn’t mess anything up. Will probably go ahead and drain the oil tonight?
 

·
Registered
Joined
·
7,102 Posts
I wouldn't do that until you are close to finished with the job. You still have to clean off all the surfaces and stuff. Might be best to get the oil changed after you clean up the crud.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #30
Good call. I’ll just change it right before get her back together and started after all this mess.

Still kinda confused on how I’d see if oil is leaking out of the cylinder, and feel like it’s in my best interest to drop the head off at the shop and get it tested for cracks either way... idk
 

·
Registered
Joined
·
7,102 Posts
Yes, you need to get the head checked for cracks...BUT we need to know if the valve(s) are the problem first.

If you pour oil on top of a cylinder, and then watch it all disappear..............then it drained past the rings. Not ideal.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #32
Ok I understand now. I was thinking about worrying where to watch the oil drip out from, but didn’t realize I could just watch the level drop in the cylinder. Duhhhhh lol thanks for the patience.

Ima preform these two tests Tn and let y’all know the results. In the meantime I found a local guy off fb that has a bunch of the same year Jeep parts. Thinking about going by and picking up all the stuff I broke or noticed needed replacement while I was pulling the head off.

I’e
intake mantifold(cracked coming out :(
Power steering pulley- mine was bent up
Missing oh shit handle
Electric fan- previously cracked

He seems to have it all so maybe we can come to a good deal.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #33
Okay guys so I did the test we where talking about and it looks like I am dealing with a leaky cylinder 2 valve.

Dropped some oil in the second chamber/ piston thing and it seems to have stayed put.

went and flipped the head upside down over a shop towel and sprayed cylinders one and two with degreaser. The fluidstarted dripping out one of the ports in the side of cylinder 2. Shown in the photo below.

what are my options to repair know knowing this? Still suspect of the head/gasket with it being a 0331 but didn’t see anything that blantantly stuck out to me besides this valve leaking and it is also on the cylinder that tested low during my dry & wet compression tests.

228347
 

·
Super Moderator
Joined
·
10,519 Posts
That is a perfect result from the requested test. Thank you. Now we know for sure the low compression was a result of the valves. It appears to be the intake valve. You can further diagnose the issue by removing the valves from the head. Usually need a special valve tool to compress the spring and remove the locks. then you can pull out the valve to see if it's bent or just fouled with carbon. If you had pressurized the cylinder when the head was still on you would have heard air leaking back through the throttle body. But given this is a 331 head, you may be further ahead by just ordering a whole new head with the valves as superman suggested. and not spend any money having a machine shop inspect it.

If you are curious about the state of the head you can buy DIY Dye Penetrant and spray the head and block to look for cracks. I am in no way endorsing the product in the link, I was just giving a suggestion. I did see a report on horsepower TV about using dyes to inspect heads for cracks. I have never used it, but 60 bucks for a dye is gonna be a lot cheaper than having a machine shop clean, prep, and magnaflux a head that is already suspect. It would be more of satisfying a curiosity.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #35
Yeah at this point I’m leaning towards ordering a new head tomorrow morning as it’s payday and I’m not really cofortable with my mechanic skills repairing intricate parts on a old Jeep head that has a higher probability than normal to crack eventually...

Not to mention the local machine shop that my gear head cousin reccomended is quoting me $400 ish for a head valve job/ clean up and $50 to test for cracks.

but also very anxious about spending that amount of money on an already top budget “fun” secondary car. Worried that after this repair this Jeep still needs work as I got a good look at things while taking it apart and a lot of wiring connections, sensors, and Vacuum lines look suspect and I she looks to be leaking oil from somewhere.

but even if I end up selling this thing I need to get it running properly And a new head on a 2000xj I feel will hold some resale Value to an educated Jeep buyer so probably worth it over patching it up.
 

·
Super Moderator
Joined
·
10,519 Posts
Investing in a new head with new valves is money well spent. Any one who knows anything about jeeps know those heads are suspect. So you replacing it will add value to the Jeep. Whether you keep it or not. Vacuum lines wiring and leaks are all part of the charm of owning an XJ. You are always welcome in our club!
 

·
Registered
Joined
·
24 Posts
Discussion Starter #37
Ok guys so I bought a reman head from J&C that will be here tomorrow I saw that it had some pretty good reviews on some threads here and was in budget.

I will also be replacing the thermostat and housing, putting on a new to me used intake mantifold and that fuel line cover peice, and looking into replacing the serpentine belt while I’m in here. My goal is get her back and running by next weekend. Fingers crossed that the exhaust headers and mantifold don’t take me as long to put in as take out, and she runs good with no codes so I can get emissions/tags

I’ll be working on it all day Sunday, and if I don’t finish will be back at it wed-Friday next week when I am working from home and have more time in the afternoon.

any cleaners/ sealants that you guys would reccomend to have on hand during this reassembly job? My supply in the garage is pretty diminished
 

·
Registered
Joined
·
7,102 Posts
Brakleen, neverseize, and you need sealant for one of the head bolts. Also, a cheap 13mm 12pt deep socket you can cut or grind down to fit the rearmost headbolt. It has to reach over the top of the stud, but also fit a torquewrench on it while remaining underneath the cowl pinch seam. A small flexible video camera (like a borescope) was my best friend when trying to get a socket on the manifold bolts.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #40
Update:

I got her back together with the reman head. And itl start up, but I need some advice on some new issues that arose haven’t had a chance to really do much as not trying to drive with this going on. Just got everything together and fluids refilled and made sure it started up.

1) pretty prevalent exhaust leak under the hood in the mantifold area. Smelled strong on start up and could actually see some fumes.

2) I over torqued and broke one of the valve cover bolts into the new head :(

3) the fuel line is leaking from a pinhole where it was held up against the manifold with that 10mm clip. Will likely do the repair outlined on this thread. Seems like a easy cheap job. Leaky Fuel Line to Fuel Rail Replacement/Fix - Jeep Cherokee Forum

however pretty bummed about the exhaust leak as that was a sob to take on and off and I don’t want to do that again. Also will probably have to take her to a shop after 1 & 3 are solved to get that bolt out I don’t want to risk ruining the new head.

How would y’all tackle this?
 
21 - 40 of 47 Posts
Top