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Cleaning out a gummed up engine, I need ideas!

xjtrailrider

xjtrailrider

NAXJA Forum User
NAXJA Member
Location
Roanoke VA
I have the 4.0 out of our MJ to put new seals, gaskets etc in and to my displeasure I found a good bit of gunked up "carbon" for lack of a better term, all over the head, rockers and even the bottom of the mains.

With the engine wide open(no pan, valve cover, timing cover), what is the best way to get this crap out without causing damage to the engine?

I have scraped out what I can but there is still plenty in there.

I have a pressure washer and could use solvents but that scares me a bit.

i could wash it down with kerosene and get what I can out of it but it would not be a very thorough job.

Give me some ideas!

I plan on cleaning it internally after its back together and running as well
 
Here is what I'm up against. The whole engine looks like this on the inside;
0623112213.jpg
 
I say, find another block..?
 
dude thats bad. i would try brake cleaner or carb cleaner. it will dry out so you dont have to worry about the fluid hurting anything. i just hope that all of that gunk isnt hiding something or plugging a leak.
 
There's stuff on the shelf called Gum Cutter that works really well for that stuff (Advanced carries it, and so does Car-Quest I think). Kerosene and other petroleum-based solvents will be fine but you won't have pressurized delivery and will have to rely on a brush or spray bolttle. You need to be careful about what you let fall into the heads, so I would turn the engine upside down and clean it that way.
 
I think you will cause more harm than good by attempting to get that out. I would reassemble and do oil changes with good oil on tight 3000 mile intervals. Lack of oil changes will get you that exact scenario.

What oil do you use? How many miles are on it? If its got any kind of miles on it I would do the timing chain while its out of the jeep.

I would go with rotella 15/40 as its designed to handle all the nasty shit diesel engines see and it may help get that cleaned up. But I think any good oil, good filter, and regular changes will completly stop it from getting worse and will probably help it clean up. If your oil is nice and black when you change it that means the detergents are doing there job and cleaning that junk out.

I tore mine down with 190K on it and it was spotless inside. Thats ugly :D
 
You certainly could leave it like that and reinstall, but if you do you need to be careful about cleaning it too aggressively, or else that crap will break loose in chunks and block your pickup. I would get it off while it's on the stand, much easier and less risky
 
Kerosene. Lots of it. Put it on and cover with a tarp so it doesn't evaporate. (Or get a big metal tub and soak the engine in kerosene. Like a watering trough.)Then apply more. Do this several times and then hit it with the garden hose. Re-apply kerosene and hit with pressure washer but don't get close. After cleaning paint the block and use a ton of WD-40 on the goodies.

Be careful with lacquer thinner as it may degrade any rubber parts and seals.
 
Turn it over so the head's pointed down about 45 degrees, lifter side down, spray kerosene
up from the bottom, brushoff what you can. I'd be leary of spraying with water, especially if it's going to be sitting around for any length of time

Here's the dilemma:
That is a pic. of an abused engine. Missed oil changes, crappy oil, no service, etc.
It would be a really good idea to get some plasti-guage and check the bearing clearances while you have it that far apart. 'Only cost the price of the plasti-gauge, and a half hour with a torque wrench. It would be a lot easier to slap a few new bearing shells in now then have a rod go walkabout later.

Also, as the interior of the engine looks like that, it might be worth it to just go ahead and dis-assemble the whole mess and really clean it. That will allow you to brush out the oil galleys.
 
It's a 4 liter not an f1 engine.

If you go measuring clearances on motors you will find 75% of this forum needs a rebuild. If it runs well put it back together and keep the oil changed. Any cleaning will just endanger it going forward IMO. To much risk in a larger chunk coming off and clogging the pickup.
 
I have only owned this MJ two weeks and the friend i bought it from only owned it a year or so. We know very little about the jeeps history.

What i ended up doing after talking to a few locals is I pressure washed it then immediately blew the engine dry, soaked it in WD40 then pumped Marvel Mystery oil through the engine by priming the oil pump with a drill with the freshly cleaned pick-up dipped into a bucket of MMO. I had my son slowly turn the engine over by hand while doing this. I have to say that i had good oil flow on all of the rockers and at each main cap.

It at least doesn't have any huge clumps of ashen oil in it now that could have stopped up the pick-up screen. I always run Rotella so that will clean it up over time.

I installed the new timing set today and started sealing the engine up. I hope to have it sitting in the MJ tomorrow

0624112241.jpg

0624112240.jpg
 
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get what you can off. like the above post make sure to watch for chunks. after you get it put back in and fill up with oil for your last quart dump a quart of atf in. i have done this before on other cars and it works very well. i run it for about 500 miles with cheap oil drain then put good oil in. it works on other cars so i dont see why it wont work on this. the 4.0 can go through alot.
 
xjtrailrider said:
I have only owned this MJ two weeks and the friend i bought it from only owned it a year or so. We know very little about the jeeps history.

What i ended up doing after talking to a few locals is I pressure washed it then immediately blew the engine dry, soaked it in WD40 then pumped Marvel Mystery oil through the engine by priming the oil pump with a drill with the freshly cleaned pick-up dipped into a bucket of MMO. I had my son slowly turn the engine over by hand while doing this. I have to say that i had good oil flow on all of the rockers and at each main cap.

It at least doesn't have any huge clumps of ashen oil in it now that could have stopped up the pick-up screen. I always run Rotella so that will clean it up over time.

I installed the new timing set today and started sealing the engine up. I hope to have it sitting in the MJ tomorrow
Click to expand...

Looks like you did well, given the circumstance... Good luck!
 
Change your filterafter the first 100 miles and cut it open to see how much of that junk is still swirling in the engine, if its not to bad get it on some MMO. I bought one gummed up just as bad, but as of right now im still having oil pressure problems
 
I'll be trying a product called Kreen by Kano Labs. I can't find a negative review on it anywhere. You may recognize the Kano Lab name as they have a very popular product called Kroil, which is a very good penetrant (next to ATF+acetone).

There are several ways to deploy the product. Most popular being to put half a quart in your crank case and drive for 1000 miles, replacing filter after 500 miles, then repeating cycle one more time. Also pour 1/2 quart in the gas tank.

Me.. I'm going to mix 1/2 quart of Kreen and 1/2 ATF and see where that gets me.

Also -- since we are on the topic. I know a lot of folks have been looking for the now discontinued Mopar CCC. I've found a gentleman over on ebay selling the same product.. only with a Valspar sticker on it. Apparently Valspar manufactured the original Mopar CCC.
 
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put some cheapie oil in it, run it until warm. Throw a can of CRC motor flush in, let it idle for 10 mins, change the oil.
 
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