Hey guys still working on my freeze plug job, the parts wont be here until monday now. So today I pulled the valve cover to get ready to change the gasket while waiting on the rest of my parts. What I found was the worse case of sludge I have personally ever seen, lol. It looks like hardened dark chocolate cake icing gunked up everywhere. Is this normal for a 4.0. I just bought the truck and by the looks of it this may be the first time the valve cover has been of the engine in the whole 162,000 mile life. Here is a crappy cell phone pic but hopefully you get the just of what I'm talking about.
Should I try to clean this up or leave it alone? I noticed that as I cleaned the valve cover gasket surface that some of the gunk was falling in the push rod hole, is that ok? What can I do to prevent this sludge problem in the future?
While some engines are more prone than others, it's never a good thing. And I would say that no, it's not normal for a 4.0. Especially to that level!
It's just plain bad in anyone's book.
Problem with cleaning it is exactly what you described. But the problem with leaving it alone does not make it necessarily any better of a solution.
Wait for some 4.0 experts to chime it, but personally I would make sure that the drainback holes are clear, then stuff something in there to plug them completely. Then scrape, gouge, chip and flush away as much of the gunk as you can.
It won't hurt much getting on the outside of the engine, so you're really just trying to make sure that it NEVER has a chance to get into the engine.
Yeah, you asked about that too, and I forgot to mention it. In answer to your previous question, yes, it's bad. Or at the very least, it's not good.
The good thing is that a lot of this stuff will eventually dissolve back into the oil as the new oil's additives take care of cleaning things. The other good news is that there is a good chance that it will either stay in the lifter gallery (pushrod holes) or the bottom of the oil pan (drainback holes).
The bad news is that it's potentially floundering around in there in harms way too.
I forgot about sealing up the pushrod holes too, in my previous description. I knew it wasn't going to be that easy! But you can plug them as well. It's just more work.
Or at the very least you can wrap towels (paper or cloth) around the rods and it can keep stuff from getting near the holes.
It's still doable. It's just a little more frustrating than I was leading it to be at first.
Of course, here's another possible bright spot. If these engines use a non-adjustable valvetrain, then it's a quick-n-easy job to remove all the rockers and rods and then it's easier to keep crud away from the holes.
I think they're probably non-adjustable, but haven't gotten that deep into them yet. So here's another good one for the experts to answer.
thanks, just plugging the push rod holes is going to get sludge in the hole. Its that caked up around them too. As far as the drain back holes go, I don't even know where they are at. Everything is too gunked up.
Once I finish all my work I was planning on running the engine and letting it get all the way to 210 which is this trucks normal operating temp from what I can tell. Then immediately draining and changing the oil, even though I just changed it. Wouldn't this melt alot of the sludge that gets through the holes back into the oil where it can be evacuated out the drain plug?
I would just try to clean as much as possible before you put it all back together. I wouldn't worry about the small amount that makes it's way back down to the oil pan. The oil pickup has a screen that protects from larger chunks making their way into the pump.
I would however start doing quality oil changes more frequently for about 10k miles. Instead of every 3k with conventional or every 6k with synthetic I would switch to a high mileage oil and change it every 2k miles and while changing the oil I would do an engine flush. This won't make it brand new inside but it will clean a large percent of it out.
That sludge is not normal, if an engine is well maintained. For comparison, I just changed my valve cover gasket a week ago on an I6 with 149k and it looked sparkling new under the cover. I didn't have to clean a thing other than some gasket residue from the head.
I always change the oil after any wrenching I do that exposes the internals.
2001 WJ 4.7/67k "Old Bones"
1997 ZJ 4.0/154k Sold
I just put rotella t5 10w-30 in it. Maybe after I finish all my work I'll swap to a full synthetic. Should I run the engine up to operating temp before changing the oil to try to get more of the junk out?
Agree with what jm said. You need to clean it while you're there.
And yes, a certain amount might fall to the new detergents or whatever in the new oils, but I would say that at this stage, the amount you actually "clean" would be so miniscule as to not make any difference.
The only real way to clean that stuff up is the old manual labor method.
The fact that you can't even see drainback holes anymore (unless these heads utilize only the pushrod holes?) and that the pushrod holes are at least partially closed down, means that any cleaning properties of the new oils are going to be minimized by the overall lack of flow to the head and back.
Do it while you're there, or just leave it be until it dies. I know which way I'd go, but either one is an option at this point.
How long do you expect to run it before you go in for a deep service/rebuild?
You circulate clean new oil interveinious through the engine for a year and wouldn't melt out that sludge nope won't happen, best thing is to just leave it alone, or pull the motor and do it right, I would button it up change the oil and move on to something else. It looks to me like the engine had been neglected, I once had a ford taurus bought for 400 bucks, neglected it for 4 years but it was only supposed to be a winter beater, I never one time changed the oil, the valve train probably looked like yours, I sold it the guy drove it away.
Deud that looks is really bad! seriously don't mess with it too much.
i try to always use a can of seafoam in the oil right before i change it, by this i mean pour half in the intake and half in the oil, and if i feel its running goofy ill split it up in the gas too
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