The Jeep 4.0 has somewhere in the 260k miles range on it. It hasn't been driven in a year, since the last time it was it had an ugly coolant leak, and I'm pretty sure it needs a water pump. In addition, the radiator is ugly inside, the coolant is mud, the lifters are noisy, and it leaks / burns oil at an impressive rate. I really should probably rebuild it, but I'd like to try some liquid restoration first. Here is the plan:

1. Charge battery / get it running.
2. Flush coolant.
3. Refill with Vinegar.
4. Change oil.
5. Add seafoam.
6. Drive for a couple of days. Keep close eye on the gauges.
7. Remove sparkplugs and put ATF in there.
8. Let it sit for a few days.
9. Remove ATF and run it until smoke clears.
10. Drain oil, remove pan, clean any crap that the seafoam dislodged from the pan, pickup, etc.
11. MAYBE remove valve cover and pressure wash sludge while both top and bottom of engine are open.
12. New rear main, new oil pan gasket, new valve cover gasket if I do 11. New water pump.
13. Flush coolant. Refill with normal coolant / water mix.
14. New oil.
15. Celebrate an engine that has less sludge, hopefully less noise, better retains it's fluids, cools better, etc.

Thoughts? Comments? I'm going to ruin it? I'm going to make it rad?

Why not give it a shot? I mean, if it already needs a rebuild, it can't REALLY hurt it, can it?

What is the ATF down the sparkplug hole supposed to do?

If it pumps oil out through all the nice new seals and gaskets in short order, the crankcase pressure is too high and it's time to punt. I'd pull the oil filler cap off it and feel how much positive pressure comes out the filler hole. if it's blowing your hair back, the rings are too worn and the new stuff won't last long.

Sky_Render wrote: What is the ATF down the sparkplug hole supposed to do?

Breaks up carbon in the rings. I've used it to good effect in Hondas in the past. Never tried it on anything else.

Jerry From LA wrote: If it pumps oil out through all the nice new seals and gaskets in short order, the crankcase pressure is too high and it's time to punt. I'd pull the oil filler cap off it and feel how much positive pressure comes out the filler hole. if it's blowing your hair back, the rings are too worn and the new stuff won't last long.

Never tried that trick.

Dude, it's a Jeep 4.0, you can't actually hurt it. I'd say your plan sounds like the most love a 4.0 will ever get, so go for it!

I'd probably skip #11. I would add in having the injectors serviced, pop on a new fuel filter, and blow out the fuel line with an air hose. The old girl could probably use a few more fresh parts, too (plugs, wires, rotor, cap, air filter, PCV valve, thermostat, and radiator cap).

What seems to actually work is just detergent additives and really long trips. I've also tried MMO soak on pistons--I don't think merely letting that sit overnight does much of anything. It needs to be hot and flowing.

The only thing that seems to dissolve sludge at room temperature and not moving is carb cleaner. I have thought about just filling an engine competely with carb cleaner and letting it sit overnight, but I am sure that wouldn't be good for any of the seals. It probably wouldn't hurt much to fill the top of the cylinders with carb cleaner through the spark plug holes and let that soak down into the pan, especially if you were going to remove the pan and clean it afterwards.

Coolant flush bottles seem to work, and I wouldn't leave those in for any extended length of time.

fresh high detergent oil and/or MMO
fresh detergent gas and/or fuel system cleaner
+2000 mile highway drive then drain.

Yeah, an injector cleaning sounds good. One of the services that disconnects the fuel line and runs cleaner through the rail as the engine runs. Should help with carbon too.

Out of curiosity - especially considering the main seal bit - is this REALLY easier than finding a JY engine with half the miles and doing a quick swap?

5, is that in the engine oil or in the gas tank?

7&8, why after you get it running? And what are you then hoping from by letting it sit there for a few days?

5 - Probably both, but I was specifically talking about to the oil.
7&8 - Mostly after it's running because I want to get it running to drive it into my shop. Where it's sitting is not a workshop. I suppose this step could be done prior to step 6 though. Letting it sit for a few days with ATF on top of the pistons gives it time to break up the carbon that is baked into the rings.

Duke wrote: Out of curiosity - especially considering the main seal bit - is this REALLY easier than finding a JY engine with half the miles and doing a quick swap?

Probably not...

Duke wrote: Out of curiosity - especially considering the main seal bit - is this REALLY easier than finding a JY engine with half the miles and doing a quick swap?

i think you miss the point...

Kinda what I figured.

I'm rather skeptical of the carbon disolving properties of ATF. There are better chemicals than ATF for that. Like seafom, probably.

I'm also not at all sure you don't end up replacing the carbon with new carbon from the burning of the ATF sitting there in top of the pistons and rings.

I've only tried it once, but it worked awesome that time. Car went from a quart every tank down to a quart every 1000 - 1500 miles.

You forgot the pills JC Whitney used to sell to seal the rings. Drop one down each plug hole and run it.

Let us know if they work..

I agree with Foxtrapper above Pull the spark plugs and use Sea Foam instead of ATF and let it sit for a few days.

I just did that to my 4A-GE in my AW11 it seemed to help with smoking as it just smokes during warm up now... (valve steam seals are shot)

Kerosene works really well. Or do the old Bardahl trick. Run their engine flush in the old oil. Drain and change the filter. Add 1 qt of Bardahl in place of 1 qt of oil. I rescued two or three engines with it.

Is Bardahl still available ? If not, Amsoil has a flush.

I like kerosene for sludge dislodging, ATF for stuck rings (works especially well on Saturns, for some reason, and I'm so cheap I like water sucked in the intake like seafoam for combustion chamber decarbonizing ( picture the clean combustion chambers you frequently see following a blown head gasket ). A little ATF mixed in with fuel is also OK at cleaning fuel injectors. Of course, you could also pull the valve covers and drop the pan and go to town with a few cans of carb cleaner...

Flogger00 wrote: water sucked in the intake like seafoam for combustion chamber decarbonizing

This, prior to (and after) the ATF soak. Just hook a port vacuum (not manifold like sea-foam) line to a tube that you stick into a water reservoir. You can even use the washer fluid reservoir. Tweak it so its just sucking in a little bit of water and drive it around like this for a while. Should get rid of carbon from the throttle body all the way to the pistons.

I've seen pics of internals from people who have done this, and the motor is like-new-shiny on the inside.

ProDarwin wrote:

Flogger00 wrote: water sucked in the intake like seafoam for combustion chamber decarbonizing

This, prior to (and after) the ATF soak. Just hook a port vacuum (not manifold like sea-foam) line to a tube that you stick into a water reservoir. You can even use the washer fluid reservoir. Tweak it so its just sucking in a little bit of water and drive it around like this for a while. Should get rid of carbon from the throttle body all the way to the pistons. I've seen pics of internals from people who have done this, and the motor is like-new-shiny on the inside.

you should also notice better detonation resistance while doing this, since you are making a home brewed water injection setup..

i like that water idea but it sketches me out a bit. i always worry ill make a mistake and BOOM goes my motor.

I either have a gummed up ring issue or valve seals gettin shot. Leaning towards rings. I might have to try your home brewed fixes.

How long should i leave ATF in the cylinders? I can get my hands on GM upper engine cleaner, and i know first hand how stupid strong that stuff is...should i just use that and the procedure written for that?

ATF for a a day or two works well on the clogged up Saturn oil rings. Crank the motor over without plugs in it a few times before you put them back in to blow out any loose E36 M3/puddles of ATF if any remains. Its best to do right before an oil change, as a lot of ATF/Carbon ends up in your oil afterward.

95% chance that is your issue and the valve seals are fine. The oil control rings on the LLO have no drainback holes :(

How much ATF to put down the spark plug holes? I've got an Astro and is a real PITA to get to the plugs, but It's been sitting for over a year and I'm trying to get it started up again. Also you mentioned refilling the radiator with vinegar? Diluted or straight? How long do you run it like that?