yellow sludge in oil fill cap

b2 · Jan 18, 2007

i just did my second oil change in my 06 KJ(6,300 miles on it). when i opened my oil fill cap i saw some yellow sludge in the tube, and some yellow/orange bubbles on the bottom of the cap. the rest of the oil that came out of the oil pan was fine(no colors/sludge). both changes that i have done have been with Mobil 1 full synthetic. anyone had any similar experiences. im hoping that those bubbles dont mean that i have coolant in my oil. thanks for your help,

dnm45227 · Jan 18, 2007

not sure if it's the case in this instance, but it could be condensation. i've seen it before on others vehicles (maybe even our old '02 kj) we've owned. either way, i was always told not to worry about it.

Marlon_JB2 · Jan 18, 2007

Condensation. Don't worry about it...

I've been told that it comes from taking lots of short trips. Well that was my case...

Eddo · Jan 18, 2007

Condensation mixed with oil. You will see it if you live in a humid climate and take lots of short trips. Had it happen to me. Seen it on other cars.

2003KJ · Jan 18, 2007

Condensation, however I would be slightly worried. Condensation that forms in the oil needs to be burned off, and this happens by the engine getting up to temperature, and the engine oil getting good and hot. If not, over time, the condensation will start to form sludge inside your engine...and that's not good. However, running Synthetic helps to cut back on the ammount of sludge that forms.

Short trips, where the engine either does not, or just barely gets completely warmed up are what causes this. Thats why I usually make it a point to drive around the block if I know i'm making a real short trip. I'd rather spend the extra in gas now then later on down the line have issues with that crap inside my engine.

cowdogg · Jan 18, 2007

It's condensation, don't worry about it. (whistle)

Dave · Jan 19, 2007

2003KJ said:
Short trips, where the engine either does not, or just barely gets completely warmed up are what causes this. Thats why I usually make it a point to drive around the block if I know i'm making a real short trip. I'd rather spend the extra in gas now then later on down the line have issues with that crap inside my engine.

That's funny as I do the same thing or combine a couple of errands into one longer trip. I change my own oil and have never noticed any condensation.

Ever notice if you change your own oil that when you take the oil filler cap off there is a removable splash guard in the filler neck. I check that too and it's always clean.

Dave

rxraptor02 · Jan 28, 2007

I noticed the sludge buildup on my oild cap/pulg thing last night when I went through the local quick stop oil change place.

I know it is Condensation however I do not make any short trips. I only have 12,200 miles on my Liberty.

The humidity is not that high right now, so is there any other explination as to why this is happening?

Dave · Jan 28, 2007

rxraptor02 said:
I noticed the sludge buildup on my oild cap/pulg thing last night when I went through the local quick stop oil change place.

I know it is Condensation however I do not make any short trips. I only have 12,200 miles on my Liberty.

The humidity is not that high right now, so is there any other explination as to why this is happening?

I wonder what kind of oil they use??? I have been using Mobil 1 and havn't had that problem. Could it be the brand or type (synthetic - verses dino) of oil that makes a difference????

I don't know, just thinking out loud here.

Dave

Marlon_JB2 · Jan 28, 2007

Dave said:
rxraptor02 said:

I noticed the sludge buildup on my oild cap/pulg thing last night when I went through the local quick stop oil change place.

I know it is Condensation however I do not make any short trips. I only have 12,200 miles on my Liberty.

The humidity is not that high right now, so is there any other explination as to why this is happening?

Click to expand...

I wonder what kind of oil they use??? I have been using Mobil 1 and havn't had that problem. Could it be the brand or type (synthetic - verses dino) of oil that makes a difference????

I don't know, just thinking out loud here.

Dave

I've heard that synthetic or dino... doesn't matter, the issue still occurs.

tommudd · Jan 28, 2007

I have run synthtic for over 15 years and have found on some models the "yellow sludge" is worse than on others. I have noticed it on mine and never worried about it . You have to think on a 20 degree day you warm up the engine shut it off, run into a store back out start up and run again how much condensation occurs, its just a natural thing.

2003KJ · Jan 28, 2007

I am also running Mobil 1 Synthetic.

To my understanding, synthetic will help to cut back on the yellow sludge, but will not eliminate it.

I never noticed that splash guard before....i'll have to look next time I change the oil.

Glad to see i'm not the only one who drives around the block to get the engine warmed up...lol.

rxraptor02 · Jan 28, 2007

I have been running a full synethic oil.

The last two time i got my oil changed was when I was visiting in Michigan and I had them use mobile 1. the time before that was Pennzoil Platinum and this last oul change was with Pennzoil Platinum.

Dave · Jan 28, 2007

There must be a common denominator that is causing this. If not the oil, and not just short trips since it occurs when only longer trips are taken, then what. There must be something?? Is it just the 3.7 liter - is it just jeeps (oh no) ....hmmmmmmm

Dave

ps - 2003kj...the splash guard (that is what I called it for lack of another name) just sits in there and lifts right out and drops right back in. Mine is an 05 so I don't know if it is in all kj's or not.

Dave · Jan 28, 2007

Ok, another thought about condensation. Water (condensation=water right?) boils at 212 degrees and the thermostat in mine must be 195 degree setting as I normally run mostly at 195 but as low as 193 and as high as 201 when at full warmed up temperature per my scan gauge.

Dave

thecause17 · Jan 28, 2007

Dave said:
Ok, another thought about condensation. Water (condensation=water right?) boils at 212 degrees and the thermostat in mine must be 195 degree setting as I normally run mostly at 195 but as low as 193 and as high as 201 when at full warmed up temperature per my scan gauge.

Dave

But water doesn't have to reach boiling point to evaporate either...that's all you'd need it to do...not necessarily boil.

Dave · Jan 28, 2007

thecause17 said:
Dave said:

Ok, another thought about condensation. Water (condensation=water right?) boils at 212 degrees and the thermostat in mine must be 195 degree setting as I normally run mostly at 195 but as low as 193 and as high as 201 when at full warmed up temperature per my scan gauge.

Dave

Click to expand...

But water doesn't have to reach boiling point to evaporate either...that's all you'd need it to do...not necessarily boil.

Ok so if not that then what? If we could figure this out mabe we could "fix it".

thecause17 · Jan 28, 2007

2003KJ said:
Condensation, however I would be slightly worried. Condensation that forms in the oil needs to be burned off, and this happens by the engine getting up to temperature, and the engine oil getting good and hot. If not, over time, the condensation will start to form sludge inside your engine...and that's not good. However, running Synthetic helps to cut back on the ammount of sludge that forms.

Short trips, where the engine either does not, or just barely gets completely warmed up are what causes this. Thats why I usually make it a point to drive around the block if I know i'm making a real short trip. I'd rather spend the extra in gas now then later on down the line have issues with that crap inside my engine.

Marlon_JB2 · Jan 28, 2007

For those of us who have no clue what we're talking about here...

You must be registered for see images attach

thecause17 · Jan 28, 2007

That's pretty nasty looking...I don't get that on mine, but then again, i don't take many short trips either...

yellow sludge in oil fill cap

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