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engine preservation

firstXJ

NAXJA Forum User
Location
michigan
I have a 93 cherokee country with a 4.0L and 190,000+ miles on it. I have a lifter that is stuck and ticking madly. Also at idle I have about 9-10lbs of oil pressure. I tried alot of tricks to get the lifter unstuck (ATF, MMO) only options left are TNT or rebuild. Since I don't have the funds for rebuild I was wondering what, if anything, can I do to help the motor last a little longer? I took the ccv out of the valve cover to look inside, all gummed up and dry. I wouldn't even know how to clean up the rockers without flushing that crap into the motor. Any and all comments are welcome and much needed.
 
I'm curious as well...
 
You probably have a collapsed lifter, worn rod/main bearings, and some degree of piston ring blowby. Since the engine is also full of sludge, I think your only reasonable option is to tear it down and rebuild it. It's the only way you're going to rejuvenate it. You'll need to do at least the following:

1. Clean absolutely everything thoroughly. That way you'll see which components are still reuseable.
2. Have the cylinders rehoned and new piston rings installed.
3. Rebuild the bottom end with new rod/main/cam bearings. You'll also need to replace the oil pump and the timing set.
4. Install new cam lifters and possibly new cam if the existing unit has badly worn lobes.
5. Rebuild the cylinder head with new valve stem oil seals and have the valves/valve seats refaced with grinding paste.

Alternatively you can buy a low mileage junkyard replacement engine or a remanufactured unit. If your budget can stretch to $2000, you can even consider a Titan Engines stroker.
 
Thanx for the info Dr. I knew that the motor needed a rebuild, just a matter of money. Right now I'm just looking for a way to help keep it going for awhile till I can save up the money for the operation. I guess my on option right now is take it really easy on her and give her frequent oil changes. Figure I'll run 20w-50 for the summer to try and save her from any more excess wear. I know it is only a matter of time, but I am just hoping to prolong the time i have with it before she gernades. This is my first cherokee, I have had it for two weeks and am truely in love with it. She is definitely a project though. gonna need to do some suspension work later, motor/trans mounts soon and rust removal from the rockers and floor pan. The rest of the rig is in great shape and for $800 I couldn't resist.

Thanx again,
Paul
 
You can clean the crud out of the top, have a shop vac with a crevice tool in one hand and a scraper in the other, work them together. The object is to prevent any bits from falling down the returns.
What brand of oil filter are you using ?
 
RichP said:
You can clean the crud out of the top, have a shop vac with a crevice tool in one hand and a scraper in the other, work them together. The object is to prevent any bits from falling down the returns.
What brand of oil filter are you using ?

That is one of the simplest ideas ever, no wonder I didn't think of that, Thanx Rich. I haven't done a oil change yet, the first one is planned next weekend. What filters are recommended? I have used Fram on previous vehicles but not sure if they are up to the task at hand. Also what oil should i use for this situation? should I go with a 20w-50 with high detergents? basically the plan is to keep her going till I can swap out the motor and rebuild it. All of that depends on money, and sadly the Wife's financial approval haha.

Paul
 
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Purolator pure one for cost, good 10W30 for oil, mobil, valvoline, castrol. If you want to get some cleaning done add two quarts of synthetic, don't bother with the syn mix. I would suggest Mobil-1 but it's a bit pricey, Castrol syntec in the 5 quart container is about $17 at walmart. The synthetic will get in and penetrate the sludge due to its smaller molecules and will over time cause it to disolve at which point it will end up in the filter so watch the dip stick and when you can't read the hash marks on the stick change the filter and add a quart.
Cleaning the top of the engine though will get rid of alot of it, it tends to dry out up there and settle, the shop vac and plastic scraper will get rid of alot of it. Just keep the vac nozzle and scraper working with each other so none of the crud gets away.
 
Looks like I have my next weekend planned now thanks. Some major TLC I think I might be able to get her to last a bit. This week I will try and price out my options up here in MI (upper penn.) for a rebuild and start my budgeting.

This site has been a huge help with all my questions. I have never been part of a site so eager to help newbies.

Thanx again,
Paul
 
Vacuum cleaner, scraper and even a set of fine screwdrivers and picks. You can plug up the openings through the head to the bottom, with plugs made of paper towel or small rags (everything you catch at the top, is less to worry about in the bottom). My head cleaned up good and then when it came time for a rear main bearing seal, I replaced the connecting rod bearings, cleaned the pump screen and had a look at the cam and whatever I could see from the bottom. My oil pressure went up 10-15 PSI average with 10-40 oil after the connecting rod bearings (sleeves).
I think the next time through, I may change out the oil pump, or at the minimum, measure the clearances and look at the gears, maybe plasti gage all the main bearings (I did a spot check last time).
All of my rockers were oiling good, but from the amount of build up on the top of the motor, it seems likely some push rod (center oil holes) may be plugged on older motors. This will sure enough make them tick and eventually the push rod may wear through the rocker arm.
A cracked exhaust manifold, will also sometimes make a ticking sound, that has fooled better mechanics than me.
A plastic tube, to listen with, can narrow down the sound. It helped me diagnose my worn connecting rod bearings, it took awhile but that's where I zeroed in. And had some plasti gage and a set of connecting rod bearings, ordered and ready, when I took the pan off.
I usually think about a rebuild when the compression gets way low and/or it starts burning oil.
 
I recently looked at the ccv on the valve cover and it is gummed up with rust colored goo. Also the the breather tube at the front of the valve cover is pushing smoke into the air cleaner box. i definitely bought myself a worn engine. There is no doubt that the rings are worn with that much blowby going on. I haven't had a compression check yet though, so there isn't any actual numbers i can report on that yet. At 190,000+ miles I would like to do everything possible to save it, but I realize that a rebuild most likely will be in order. I will definitely do the above mentioned thorough cleaning and anything else anyone can suggest to keep her kicking.

Paul
 
After you get it cleaned up a bit, dump a pint of gear Moly into the motor with the oil. It will coat the insides and won't actually hurt anything and it just might help some. At least around here, true Moly is getting hard to find, it kind of looks like metalic grey/black snot.
Blow backwords, through the two vent holes in the valve cover and see if they aren't restricted, the same the other direction.
I've got an 87 4.0 in the garage ( a spare), that has never had anything but synthetic run in it. The inside of the motor still looks new, with very little wear.
For the last 30,000 miles I've been waiting for my old neglected (previously owned) 4.0 to die. It just keeps on keeping on and hasn't flunked a smog test yet? Though it is getting seriously tired, it still runs rather well.
 
you have any manufacture names for the gear moly? do you put it in and leave it in or run it for awhile and change out the oil after XXXXmiles? ever have it clog up in constricted areas of the block/head?
 
I think it is actually half a pint, it's sized for use in a tranny or differential. Liquid Moly makes some, though what they sell looks a little watered down, if it is in fact real Moly.
I don't think there is any more chance of the Moly causing a restriction, than any of the other junk in the motor. True Moly adhears well and coats the insides of whatever. Which in my mind makes more sense than a thicker oil that the pump, has to work harder to pump and takes awhile to get to the top of the motor. I've tried a couple of loads of 10-50 in various motors and always noticed a little clatter, until the lifters pumped up or the top of the motor oiled.
I put Liquid Moly in my motor, as a stop gap, before I changed the rod bearings out. It quieted down the motor by about fifty percent. I've used it in differntials, as a stop gap till I could change out whatever bearing was making noise.
I did notice some oil pressure spikes, after I cleaned the top and bottom of my motor out. I was really carefull, but likely left some gunk that got sucked up by the pump anyway. It happend after I changed the oil out with the Moly in it, I doubt the Moly was a factor.
Everything is fine now, though the oil pressure jumping around on occasion, did make me nervous.
I'm still kind of torn, between cleaning out the old junk and leaving a sleeping dog lie. I cleaned mine out, but it did make me nervous.
I've seen guys ruin there motors, using flushes on a really gunked up motor and then running it with a plugged oil pump screen. The oil passeges from the filter, to the cam, rods and mains aren't really very large.
There really isn't any snake oil cure for a motor that needs rings. Though my compression has actually gone up, since I've had my 88 XJ.
 
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Not plugging but you might check out that Auto-RX stuff. The guys over on
"bob is the oil guy" .com seem to think very highly of it. Theres quite a few before/after photos of peoples valve trains etc.... Im tryin it now on my 01 and well see what happens. It has a money back guaruntee if not satisified so i figured what the heck.
 
Since you are considering a rebuild and if I were you I would get some motor flush and pour it in and run it for a few hundred miles,dump it,fill up with castrol syntec and RESTORE brand oil substitute....I have used restore personally and I ended up with better compression numbers than I started with on a 89 4.0 with 170,000 miles.Best of all this only costs a few bucks and it's non-invasive....if you get my drift.
 
firstXJ said:
I recently looked at the ccv on the valve cover and it is gummed up with rust colored goo. Also the the breather tube at the front of the valve cover is pushing smoke into the air cleaner box. i definitely bought myself a worn engine. There is no doubt that the rings are worn with that much blowby going on. I haven't had a compression check yet though, so there isn't any actual numbers i can report on that yet. At 190,000+ miles I would like to do everything possible to save it, but I realize that a rebuild most likely will be in order. I will definitely do the above mentioned thorough cleaning and anything else anyone can suggest to keep her kicking.

Paul

OK, since funds are low, here's what you can do over a weekend to keep the old girl chugging along for a little longer.

Saturday:

1. Remove the valve cover and clean the insides thoroughly (including the CCV baffles).
2. Remove both CCV grommets from the valve cover and let them soak in gasoline to dissolve all the grunge. Then blow compressed air through them to remove any remaining gubbins.
3. Remove all the rocker arms with bridges, soak in gasoline to remove caked on sludge, and check for worn/damaged rockers.
4. Remove pushrods, soak in gasoline, and check if any are bent or have worn tips. Blow compressed air through the oiling holes to clear them.
5. Clean as much sludge from the top of the head as you can. A shop vac would be useful to suck up debris before it falls down oiling holes.

Reassemble everything using a new valve cover gasket and replace any worn/damaged parts that you may find. With the valve cover off, you can diagnose a collapsed lifter (pushrod will feel loose and valve spring won't compress fully).

Sunday:

1. Drain oil and remove oil pan (you'll need to jack up the Jeep by the frame rails to let the front axle droop, remove the starter, remove the steering damper, remove the engine mount bolts, and lift the engine with a jackstand underneath the crank pulley (put a block of wood between the jackstand and the pulley to avoid damaging it).
2. Clean the inside of the oil pan thoroughly until all the caked on sludge is removed.
3. Remove the old oil pump assembly and replace with a new one.
4. Replace old rod bearings with new 0.001" undersize units.
5. Reinstall the oil pan and bolt everything else back up. I recommend the Victor-Reinz one piece rubber oil pan gasket.
6. Replace the oil filter.
7. Add 6 quarts of 20W-50 dino oil.
8. Remove coil lead to distributor and crank the engine for a few seconds to prime the oil pump & filter.
9. Reattach coil lead.
10. Cross your fingers.
11. Fire up the engine.

Good luck. Hopefully you'll gain some oil pressure, the valvetrain noise will be reduced, and you might alleviate the blowby problem (for now).
 
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Dr. Dyno said:
OK, since funds are low, here's what you can do over a weekend to keep the old girl chugging along for a little longer.

Saturday:

1. Remove the valve cover and clean the insides thoroughly (including the CCV baffles).
2. Remove both CCV grommets from the valve cover and let them soak in gasoline to dissolve all the grunge. Then blow compressed air through them to remove any remaining gubbins.
3. Remove all the rocker arms with bridges, soak in gasoline to remove caked on sludge, and check for worn/damaged rockers.
4. Remove pushrods, soak in gasoline, and check if any are bent or have worn tips. Blow compressed air through the oiling holes to clear them.
5. Clean as much sludge from the top of the head as you can. A shop vac would be useful to suck up debris before it falls down oiling holes.

Reassemble everything using a new valve cover gasket and replace any worn/damaged parts that you may find. With the valve cover off, you can diagnose a collapsed lifter (pushrod will feel loose and valve spring won't compress fully).

Sunday:

1. Drain oil and remove oil pan (you'll need to jack up the Jeep by the frame rails to let the front axle droop, remove the starter, remove the steering damper, remove the engine mount bolts, and lift the engine with a jackstand underneath the crank pulley (put a block of wood between the jackstand and the pulley to avoid damaging it).
2. Clean the inside of the oil pan thoroughly until all the caked on sludge is removed.
3. Remove the old oil pump assembly and replace with a new one.
4. Replace old rod bearings with new 0.001" undersize units.
5. Reinstall the oil pan and bolt everything else back up. I recommend the Victor-Reinz one piece rubber oil pan gasket.
6. Replace the oil filter.
7. Add 6 quarts of 20W-50 dino oil.
8. Remove coil lead to distributor and crank the engine for a few seconds to prime the oil pump & filter.
9. Reattach coil lead.
10. Cross your fingers.
11. Fire up the engine.

Good luck. Hopefully you'll gain some oil pressure, the valvetrain noise will be reduced, and you might alleviate the blowby problem (for now).

Totally agree on the sat part, not too much trouble to get into as long as you have a torque wrench. Sunday on the other hand might be an issue, depends how comfortable he is with playing with bearings AND fighting the oil pan to get it off. But he would be able to get at alot of the grunge in there thats for sure.
 
great advice guys. gonna price the parts and tools out today and compile the shopping list. As for the main bearings I will have to see what is involved in the removal/replacement. Been awhile since I had to deal with them.
All the advice and suggestions are extremely helpful guys keep them coming. I'll get her straightened out soon enough!

Thanx,
Paul
 
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