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  #1  
Old July 23rd, 2021, 09:19
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splitz splitz is offline
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Cleaning Sludge

I am replacing my valve cover gasket and I was greeted by this:




The sludge is so bad I can wipe it off in chuncks.

What's the best way to clean this up?
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  #2  
Old July 23rd, 2021, 10:42
RCP Phx RCP Phx is offline
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Re: Cleaning Sludge

You'll need to pull the pan too, but I use nothing but diesel.
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Old July 23rd, 2021, 11:34
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Anak Anak is offline
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Re: Cleaning Sludge

I found a similar situation with the '97 ZJ I picked up for The Varmints.

We did a lot of physical cleaning, and I am now working at it from a chemical cleaning (Marvel Mystery Oil) angle.

https://www.naxja.org/forum/showthread.php?t=1159696
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  #4  
Old July 23rd, 2021, 13:45
tech1001 tech1001 is offline
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Re: Cleaning Sludge

I would remove all the rocker arms and clean them also you can use a brush and clean the head , diesel fuel will work good but it will wash it down to the the oil pan . Then you will have to remove the oil pan and clean it all out and when in the oil pan you can replace the oil pump because it has been pumping all that old oil and I would think it is worn pretty bad . How many miles on your XJ ?
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Old July 23rd, 2021, 13:56
Unclewolverine Unclewolverine is offline
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Re: Cleaning Sludge

I've seen worse. A few short oil changes with rotella would probably clear a lot of it up.
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  #6  
Old July 23rd, 2021, 13:59
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Re: Cleaning Sludge

Oil pump screen will need cleaning or replaced
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  #7  
Old July 24th, 2021, 06:53
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Re: Cleaning Sludge

5 quarts of Rotella T4 and a quart of Marvel Mystery Oil, Wix 1085 filter.
Monitor the sludge melting away through the oil filler hole. DON"T start scraping it off or disassembling the valve train. Run it at least 1,000 miles before changing. Go longer if you can.
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Old July 24th, 2021, 07:43
RCP Phx RCP Phx is offline
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Re: Cleaning Sludge

Youv'e had this xj for years and your just seeing this?
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  #9  
Old July 24th, 2021, 09:47
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splitz splitz is offline
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Re: Cleaning Sludge

Quote:
Originally Posted by tech1001 View Post
I would remove all the rocker arms and clean them also you can use a brush and clean the head , diesel fuel will work good but it will wash it down to the the oil pan . Then you will have to remove the oil pan and clean it all out and when in the oil pan you can replace the oil pump because it has been pumping all that old oil and I would think it is worn pretty bad . How many miles on your XJ ?
It's got about 130k.

I started to look at dropping the pan and replacing the oil pump after you and the others mentioned it. The oil pressure drops down to 10 psi at idle, and some have said that replacing the pump also fixed their low oil pressure issue at idle.

Quote:
Originally Posted by cruiser54 View Post
DON"T start scraping it off
What are the dangers of getting the big chunks wiped out of the valve train?

Quote:
Originally Posted by RCP Phx View Post
Youv'e had this xj for years and your just seeing this?
Yeah, this is the first time I've pulled the valve cover. I rarely drive it. I've put on less than 20k miles in the 13 years I've owned it...wow, I've had this thing a long time.
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Old July 24th, 2021, 09:34
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cruiser54 cruiser54 is offline
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Re: Cleaning Sludge

Good catch RCP.
Everyone should shine a flashlight into the oil filler hole when they get a "new to them" vehicle. Maybe before they buy it...

That said, it's easy to remedy with the Rotella and MMO. And, easy to monitor.
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  #11  
Old July 24th, 2021, 09:50
RCP Phx RCP Phx is offline
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Re: Cleaning Sludge

Quote:
Originally Posted by cruiser54 View Post
Good catch RCP.
Everyone should shine a flashlight into the oil filler hole when they get a "new to them" vehicle. Maybe before they buy it...
This ^^^^^^^ plus it applies any time your changing the oil!
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  #12  
Old July 24th, 2021, 09:51
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cruiser54 cruiser54 is offline
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Re: Cleaning Sludge

It's been running this long with low oil pressure....
IF the gauge is accurate. If you hadn't pulled the valve cover, you'd be happily driving the crap out of it, right?

Leave the chunks alone. That stuff can drop into the oil pan and get sucked up to the oil pump strainer. If it hasn't blown up by now, which I doubt it would have, what's the harm in doing the Rotella and MMO thing?

I've done it numerous times and it worked like a charm.
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  #13  
Old July 24th, 2021, 10:53
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splitz splitz is offline
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Re: Cleaning Sludge

Quote:
Originally Posted by cruiser54 View Post
It's been running this long with low oil If you hadn't pulled the valve cover, you'd be happily driving the crap out of it, right?
Sigh, I suppose you are right.
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