Super sludge in a 4.0 jeep engine, need advice.

[Clevy]

Originally Posted By: FLORIDA
Lots of good info here guys thanks. I'm not going to pull the pan, its just to hard of a job on this vehicle for my skill set and driveway. I am torn between just going with short interval oil changes or first using some kind of cleaner in the engine to get more sludge out. It seems like a split here, some would do it one way and some would do it another.


Follow trav's advice. The carb cleaner sitting in the oil an overnight insures a clean oil pick up screen.
He is an expert and I would follow his advice especially considering he is a professional and in real life if his method doesn't work the customer returns and costs him money doing things twice.

 

[FLORIDA]

I already put the valve cover on. Can I still follow travs advice and add the carb cleaner to the normal oil fill cap on top of the cover?

 

[zerosoma]

Pour iso heet and diesel treat down the filler hole and run it for 5 minutes.

I don't know what it will do but maybe it would be fun. Sucks you got a sludger. Hope it works out for you

 

[ARB1977]

Slower is better.

 

[Clevy]

Originally Posted By: FLORIDA
I already put the valve cover on. Can I still follow travs advice and add the carb cleaner to the normal oil fill cap on top of the cover?


You could but you won't get the tops of the rocker arms bathed in it.
I suggest getting it soaked the best you can and order some kreen,then stock up(5 gallon pail) of oil from wal-mart and go with 1000 mile oil change intervals and use an idle type flush at the end of each interval.
I'd also buy alot of filters,and find some that aren't that efficient,since you will end up clogging them very quickly.
If kreen isn't an option seafoam can be bought by the gallon. Substitute it for kreen.
While using these flush products I suggest driving easy and not revving high for long.

 

[yonyon]

On a Jeep 4.0 it really isn't that great of a task to pull the valve cover back off. It hasn't been on long so you'll be able to reuse the gasket without issue.

His technique is well thought out and really sounds like the safest approach, even safer than the "just change your oiil more frequently" method because you get a clean pickup screen right away. It's also going to be the fastest way to get a lot of sludge out without doing a lot of disassembly.

 

[RF Overlord]

Originally Posted By: Garak
ATF is neither high in detergents nor is it designed for your engine. Ignore suggestions to use it; keep it out of there. The Rotella you've selected doesn't need any "help."
^^^This.

Where did people get the idea that ATF is a good cleaner? Is this another of those "my grandfather's cousin's mechanic told him to do it" myths?

 

[meep]

I bought a 4.0 that was FAR WORSE. It had so much sludge built up in it that in looked all smooth, like peaceful rivers in soft sand... no bumps or changes in the surface suggested that bolts/studs were lurking beneath. It had a history of overheating.

I cleaned it out with a screwdriver, then vacuumed it. I also used the vacuum crevice tool to try to get the drain holes in case any fell down there (they were unobstructed when I started).

Removal of the sludge improved the leaky valve seals, which I suspect were starved for oil due to the sludge buildup.

There were far worse problems with this motor, but it was reliable even after that kind of previous history. Head was leaky--- found the bolts all 25lbs below spec and all studs about 10lbs below spec. tightened all to 10 over and ALL of my engine-related coolant leaks stopped.

ANYWAY the one oddity I found was this. Mine was before the '96 redesign that quieted the valvetrain, and man it was noisy. Due to high consumption I tried 10-40 maxlife, 15-40 rotella, after the initial 10-30 maxlife. Regardless of the oil, 1/2qt of 0-20 synthetic would immediately quiet it down for the duration of that run of oil. I used whatever oils were picked up on sale, so castrol and PP were probably the 20's that I tried this with. A splash of either made this strange difference that I never really could explain.

When I bought it, it needed a quart per week and 1/2 gall coolant per week. I sold it a year later (and have always regretted selling it). It was such a fun vehicle, and was my Daily Driver-- sold it with 249,000 miles on it. By then I had to check coolant monthly, and it needed maybe 1/2qt per month.

These are stout engines!

Change the Transmission Fluid/Filter. Wants ATF+4, or amsoil. The castrol ATF+4 works nicely. If it's weak and starts to slip, Lucas can help as a last effort. (mine used the AW4, so it was a different animal).

My T-case did well on mobil ATF (I had the 2H, 4FullTime, 4PartTime, N 4L flavor).

TMy Dana 30/35s were pretty beat. they didn't care what went in there. I went with a thicker synthetic.

Also suggest turkey-basting the PS fluid out, refreshing that lube.

Frankly this is probably my favorite vehicle of all time! Enjoy it!

Mike

 

[951Indy]

If it has an oil pressure gauge, just keep an eye on it. IF the pickup starts to clog, you'll know. My bet is the high detergent oil will disperse anything that gets in the screen and get it to the filter.

Just my opionion, but put it back together and do the short OCI thing. No potions, no magic, no mail order. Just run it.

 

[84zmyfavorite]

Geez, If it were me, I would either go super easy and do short OCIs, or go All the way and Rebuild the motor. Im currently working on my Gold 2000 Cherokees 4.0 that ran for a long time before I got it with a Severely Cracked 0331 head that looked similar to your 4.0s drivetrain, but with a milk chocolate brown color to the sludge(mix of Ooold oil and coolant). I currently have 7 Cherokees, 5 of which have the 4.0, 4 of which are running/driving and all get babied. I have ALOT of respect for this engine, and cant abuse them anymore like I used to. My 84 with the GM 2.8V6 on the other hand,...is proabably filled with sludge to the tops of the valve covers.

 

[CarbonSteel]

Originally Posted By: Trav
Originally Posted By: FLORIDA
Lots of good info here guys thanks. I'm not going to pull the pan, its just to hard of a job on this vehicle for my skill set and driveway. I am torn between just going with short interval oil changes or first using some kind of cleaner in the engine to get more sludge out. It seems like a split here, some would do it one way and some would do it another.

The bottom line is you need to make 100% sure the pickup screen remains clear. Cleaning the head as i described is easy and can be done with a minimum amount of tools.
Using the cleaner in the pan will liquefy anything in there and also the screen with zero effort on your part.
Its your engine and you do as you see fit but keep in mind if the screen plugs its pretty much a done deal, used engine or rebuild time.

IMHO this engine is probably beyond short OCI and in the sump as you drive cleaners.

+1 - Trav is correct; the Berryman will definitely dissolve the sludge leaving squeaky clean metal behind. Use of this in the sump is important to prevent the pick-up screen from clogging (which will destroy the engine in very short order).

There have been a number of these occurrences posted here and on other websites and **usually** cleaning oils like PYB or PU will have little effect on sludge like this as it has coked and is not easily dissolvable by engine oils. A stronger cleaner is needed and I have built enough carburetors in my time to state unequivocally that Berryman will almost instantly dissolve any sludge it touches. Good luck with your project--hopefully you can save it!

 

[84zmyfavorite]

Man, I wouldnt drive it with that Berryman in it. Use cautiously, I would say. GUNK has same thing basically. I think AUTO_Rx would be your safest bet. Or just leave it. That might be the safest. Or rebuild it! You might have to do that if You try Chemical Cleaning it.

 

[FLORIDA]

I'm not going to run it with berryman in it. Its just going to soak in the pan and then be drained and filled with new oil before being ran.

 

[sgvaibhav]

if slude is magnetic, use a super magnetic screwdriver or a super magnetic poke stick to pull out easily

i dont know if slude is magnetic

 

[84zmyfavorite]

Depending on the amount of wear metals, Iron in particular, that just might work. But, I kinda hope not...

 

[84zmyfavorite]

4.0s do shed alot of Iron at times, though. If it was driven by 1 of those 5w-30 enthusiasts, that might work!

 

[Bladecutter]

Since you already have the valve cover back on, here's what I would do:

Drain the engine oil, and reinstall the drain plug.
Pour two full gallons of Berryman's cleaner into the oil filler hole, and let it sit over night.
Drain the sludge filled cleaner into a clean pan capable of holding 2.5 gallons of oil, reinstall the drain plug, and repour that used cleaner back into the oil filler hole.
Let it sit overnight again.
Pop off the valve cover and take a look at the condition, and post pictures.

If it's much cleaner, drain the cleaner from the oil pan, and take the third gallon jug, and lightly clean as much sludge off of the top of the engine using whatever you have on had to do it. Toothbrushes are cheap, and soft, but buy a bunch of them.

If it's already sparklingly clean, drain out all of the cleaner, pour fresh oil all over the valvetrain, put the valve cover back on, fill with more fresh oil, install a new oil filter, and then start up the truck, letting it idle for 20 minutes.

Drain that oil, pour in more brand new oil, add another brand new oil filter, and drive the car like normal for 500 miles. Then do another oil and filter at a more reasonable 3000 miles.

BC.

 

[yonyon]

Originally Posted By: Bladecutter

Pour two full gallons of Berryman's cleaner into the oil filler hole, and let it sit over night.

That sounds like a lot. The level needs to be below any gaskets or seals.
Originally Posted By: Bladecutter

Drain the sludge filled cleaner into a clean pan capable of holding 2.5 gallons of oil, reinstall the drain plug, and repour that used cleaner back into the oil filler hole.
Let it sit overnight again.

So drain it out then immediately pour it back in and then let it sit overnight again? Why not just leave it where it is?
Originally Posted By: Bladecutter

Pop off the valve cover and take a look at the condition, and post pictures.
If the valve cover is going to come back off, shouldn't that happen at the beginning to clean the top before the soak that ensures a clean pickup strainer?
Originally Posted By: Bladecutter

If it's much cleaner, drain the cleaner from the oil pan, and take the third gallon jug, and lightly clean as much sludge off of the top of the engine using whatever you have on had to do it. Toothbrushes are cheap, and soft, but buy a bunch of them.

So now you want to knock loose any sludge left up top and let it go where it may. I don't think your plan makes as much sense as Trav's method.

 

[Trav]

Originally Posted By: yonyon
That sounds like a lot. The level needs to be below any gaskets or seals.

+1 The level must be below seals and gaskets.
OP as others have said..Normal oil level in the pan e.g. 5 qts is plenty and just leave it to do dissolve anything in the pan.

Originally Posted By: 84zmyfavorite
Man, I wouldnt drive it with that Berryman in it. Use cautiously, I would say. GUNK has same thing basically. I think AUTO_Rx would be your safest bet. Or just leave it. That might be the safest. Or rebuild it! You might have to do that if You try Chemical Cleaning it.


You obviously didn't bother to read the postings. No one advocated driving it with the cleaner. Gunk is Kerosene based and not effective on this.
ARX will do nothing for this engine (or any other for that matter) and it certainly wont clean the pick up.

Done in the manner outlined it will not need a rebuild from doing this procedure.
I did multiple Honda engines this way and posted lots of pictures, one engine has since gone another 100K 100% problem free, it doesn't use or leak a drop of oil.
This is powerful stuff but like a lot of things when used properly is harmless but very effective and fast acting.

 

[rvt]

Originally Posted By: Chris142
I think its past the point of cleaning. Id put it back together and run it till it dies if it ever does.


I agree. This was far more common back in the '60s and earlier. I've seen worse.

Couple things I'd do- Check to make sure the thermostat is functional and at the right opening temperature.

Not worry about cleaning it, but start changing oil on a regular basis.

Plan on cylinder bore wear and an eventual overhaul. But my experience has been these engines can go a surprisingly long time in the present condition (with luck). I had a Chevy inline six go about 50K miles with more sludge than yours (after starting regular oil changes).