Sludge

Slepnir

Member
Joined
Apr 18, 2016
Messages
98
Location
Seattle
20170219_014941.jpg
went to replace the wife's valve cover gasket and vwala...chunky maple syrup. We do regular oil changes ever 3000 miles and occasionally add a quart of mystery oil. Not sure what to do here. Not even sure if I want to find out what is hiding under all this sludge. It's a 2001 tj and she just made the last payment on it and we've had the jeep for 3 years. Drives fine no smoke though she says the oil pressure jumps up when she gives it gas but nothing crazy. Only issue we ever had was the fuel pump and I fixed that and it wouldn't go into 4 wheel drive but I fixed that yesterday. The only thing I can do right now is clean what I can and button it up so she can drive it to work today when she wakes up. I've never seen anything like this before and I don't even know how much sludge would be considered bad. Engine flush? I heard bad things about them. What are your recommendations? Thanks in advance
 
20170219_014953.jpg heres another picture of it. When I change her oil I'm gonna pull the pan and see what it looks like from underneath. Might be later today or tues. It's 0330 in the morning and I'm about to call it quits for now.
 
Last edited:
Seems maybe the PO(s) may not have maintained it properly. Not sure how to handle this. I don't like adding "flushing" chemicals to the oil (MMO, Seafoam, Kerosene)for fear of clogging the oil pump and/or oil passage ways in the engine.
 
Last edited:
  • Like
Reactions: Slepnir
You've had it for a few years and have been doing oil changes more frequently than the usual 5000 mile oil changes and you still have sludge. What kind of oil are you using? Also, you mentioned that it is running well so I guess there are no ticking noises or misfiring? Finally, is it losing coolant anywhere? Mine was losing coolant for a while due to either a leaking head gasket or a cracked head. I didn't do anything about it and at 160,000 the oil pressure started to drop to zero at idle. When I had the engine replaced, the mechanic told me there was a lot of sludge. He felt it was due driving it around with coolant leaking into the oil although I didn't see any sign of that.

To go back to your original question, you can scoop out as much as you can with your fingers, toothbrush or whatever you have. Taking off the oil pan and cleaning underneath would be helpful as well. There's lots of magic chemicals at Pepboys but none of them will truly get it completely clean if they do much good at all.

Since I had nothing to lose with my engine, I took the drastic step of draining 4 quarts of oil and putting in 4 quarts of diesel fuel. I would not do this on a good engine. I idled it for one hour. The ticking noise stopped and it removed a lot of sludge but there was still a lot left.
 
  • Like
Reactions: Slepnir
Oh goodness, that's really, really horrible sludge!

I'm not an advocate of additives, but in this case I think it might be worth it to buy something and put it in there (before you change the oil) to see if it will get rid of any of that sludge, because that's bad!

As @RedTJ suggested, you should definitely try to clean every bit of it you can while you have the valve cover gasket off, and if you want to drop the oil pan, that would be a good idea as well.

I'm just not sure how one even gets to that level of sludge!
 
  • Like
Reactions: Slepnir
You've had it for a few years and have been doing oil changes more frequently than the usual 5000 mile oil changes and you still have sludge. What kind of oil are you using? Also, you mentioned that it is running well so I guess there are no ticking noises or misfiring? Finally, is it losing coolant anywhere? Mine was losing coolant for a while due to either a leaking head gasket or a cracked head. I didn't do anything about it and at 160,000 the oil pressure started to drop to zero at idle. When I had the engine replaced, the mechanic told me there was a lot of sludge. He felt it was due driving it around with coolant leaking into the oil although I didn't see any sign of that.

To go back to your original question, you can scoop out as much as you can with your fingers, toothbrush or whatever you have. Taking off the oil pan and cleaning underneath would be helpful as well. There's lots of magic chemicals at Pepboys but none of them will truly get it completely clean if they do much good at all.

Since I had nothing to lose with my engine, I took the drastic step of draining 4 quarts of oil and putting in 4 quarts of diesel fuel. I would not do this on a good engine. I idled it for one hour. The ticking noise stopped and it removed a lot of sludge but there was still a lot left.
That's what I'm scared of. She is losing coolant but it's from a small pinhole size crack in her radiator. (Another item on the list of things to do to her jeep)I thought about that last night but her oil is just dark and not like coffee with creamer so I didn't suspect a head gasket leak. When I was trying to clean it off it was sticky like someone poured maple syrup in it instead of oil. Was yours like that? Oh correction on the mmo. I usually do her oil change and use Mobil10w30 and occasionally put a qrt of mmo, but that was before I left. When I was gone she was getting her oil changed at walmart and they were putting castroil 5w30. I'll have to see what it looks like underneath when I drop the pan. I was thinking of changing her oil and filter and putting mmo in it and drive it to work since my my job is 80 miles round trip and let her drive my jeep since hers is 5 miles and she rarely gets it on the hwy. Do that for a week and drain the oil and drop the pan and clean what I can. Maybe even do this a few times to see if it cleans some of that crap off. What do you think? I'm cringing at the fact I'm letting her drive my rig.
 
View attachment 11155 went to replace the wife's valve cover gasket and vwala...chunky maple syrup. We do regular oil changes ever 3000 miles and occasionally add a quart of mystery oil. Not sure what to do here. Not even sure if I want to find out what is hiding under all this sludge. It's a 2001 tj and she just made the last payment on it and we've had the jeep for 3 years. Drives fine no smoke though she says the oil pressure jumps up when she gives it gas but nothing crazy. Only issue we ever had was the fuel pump and I fixed that and it wouldn't go into 4 wheel drive but I fixed that yesterday. The only thing I can do right now is clean what I can and button it up so she can drive it to work today when she wakes up. I've never seen anything like this before and I don't even know how much sludge would be considered bad. Engine flush? I heard bad things about them. What are your recommendations? Thanks in advance
Wow! Mine looked nothing like that, I was surprised as to how darn clean it was.
I wonder what caused it if you've been doing proper maintenance cycles?
 
My oil never looked like that either but toward the end, I could see just a little bit of white stuff around the oil fill. When I pulled off my valve cover it looked like your pictures. obviously the rad needs to be fixed. Once it is, keep an eye on the coolant.
 
I wonder if her short drive cycle might contribute to that level of sludge. If the engine never gets to operating temps for a decent amount of drive time would it make the build up stick to cooler spots in the valve cover area and pan? I have only seen build up like this once in a friends car he got from his grandmother when she passed. Regular maintenance from the dealer, but she just drove short distances and infrequently at that. Jus throwing it out there.....
 
  • Like
Reactions: Slepnir
View attachment 11155 went to replace the wife's valve cover gasket and vwala...chunky maple syrup. We do regular oil changes ever 3000 miles and occasionally add a quart of mystery oil. Not sure what to do here. Not even sure if I want to find out what is hiding under all this sludge. It's a 2001 tj and she just made the last payment on it and we've had the jeep for 3 years. Drives fine no smoke though she says the oil pressure jumps up when she gives it gas but nothing crazy. Only issue we ever had was the fuel pump and I fixed that and it wouldn't go into 4 wheel drive but I fixed that yesterday. The only thing I can do right now is clean what I can and button it up so she can drive it to work today when she wakes up. I've never seen anything like this before and I don't even know how much sludge would be considered bad. Engine flush? I heard bad things about them. What are your recommendations? Thanks in advance
I can tell you a few things that im certain of based on the picture and your stated oil change interval.

1) this is not the primary result of a coolant contamination into the oil system. If it were, it would look like coffee with heavy creamer.

2) nor is it a result from your oil change intervals. 3000 miles is not long enough to even begin using up the detergent additives in the oil that prevent this from happening.

I ran an auto quick lube facility for years and can honestly say I've personally done at least 20,000 oil changes on several thousand different vehicles and have pretty much seen it all when it cones to vehicle fluids.

This is a case of a previous owner going way way too long on regular crude based oils. Although it only takes one instance for a massive sludge buildup to occur, this is most likely a result of several long term change intervals to cause this build up.

I don't recommend using motor flushes, as they are extremely aggressive and in order to be effective they need left in for long periods of time to work and usually take multiple applications. During that time your engine is running with the cleaner, it is also breaking down the fresh oil it's mixed with. It's also impossible to get 100% of the oil out of an engine without a complete disassembly. There is always leftover dirty oil that is mixed with the new oil added, and you really dont want any of that remaining. Another unintended result of using flushes / cleaners , is that on older higher mileage engines, the flush will dissolve sludge deposits that are plugging up previously unknown gasket leaks. Now your faced with another problem, addressing oil leaks.

In your case, I would remove the head and thoroughly clean everything, as well as drop the oil pan and clean the oil pick up tube and screen.
 
Last edited:
I wonder if her short drive cycle might contribute to that level of sludge. If the engine never gets to operating temps for a decent amount of drive time would it make the build up stick to cooler spots in the valve cover area and pan? I have only seen build up like this once in a friends car he got from his grandmother when she passed. Regular maintenance from the dealer, but she just drove short distances and infrequently at that. Jus throwing it out there.....
I just read about that also contributing to sludge and condensation of water not being able to evaporate in that short time. I also read starting up a vehicle till warm and then just shutting it off..(What my wife does to my jeep when I'm deployed) ...is bad as well and contributes to sludge as well.
 
I can tell you a few things that im certain of based on the picture and your stated oil change interval.

1) this is not the primary result of a coolant contamination into the oil system. If it were, it would look like coffee with heavy creamer.

2) nor is it a result from your oil change intervals. 3000 miles is not long enough to even begin using up the detergent additives in the oil that prevent this from happening.

I ran an auto quick lube facility for years and can honestly say I've personally done at least 20,000 oil changes on several thousand different vehicles and have pretty much seen it all when it cones to vehicle fluids.

This is a case of a previous owner going way way too long on regular crude based oils. Although it only takes one instance for a massive sludge buildup to occur, this is most likely a result of several long term change intervals to cause this build up.

I don't recommend using motor flushes, as they are extremely aggressive and in order to be effective they need left in for long periods of time to work and usually take multiple applications. During that time your engine is running with the cleaner, it is also breaking down the fresh oil it's mixed with. It's also impossible to get 100% of the oil out of an engine without a complete disassembly. There is always leftover dirty oil that is mixed with the new oil added, and you really dont want any of that remaining. Another unintended result of using flushes / cleaners , is that on older higher mileage engines, the flush will dissolve sludge deposits that are plugging up previously unknown gasket leaks. Now your faced with another problem, addressing oil leaks.

In your case, I would remove the head and thoroughly clean everything, as well as drop the oil pan and clean the oil pick up tube and screen.
I was afraid of that. I'm about to leave again and as soon as I get back I'll be transferring so I have no time to do all that. Was hoping someone had a miracle cure haha ..reality check lol. I won't be using any motor flushes though now. She'll just have to make due for now. I wouldn't mind getting a new engine or rebuilt engine at my next location to swap out with hers when the time comes and just clean up and rebuild sludge bucket as a spare/learning project. That's her new nickname for her jeep. but it's running good and strong for now so I'm hoping it stays that way until I can do something. I just hope I get to stay in the area so I don't have to worry about her jeep getting across country worst case scenario. Then again those 4.0l just seem to keep going. Thanks for the advice. I do appreciate it.