Help!! Sludge......

[4x4Xtreme]

I changed my oil about 2 months ago, got about 2000 miles on it since. I noticed today while checking things out under the hood that I have a huge sludge buildup just inside the oil cap. Anyone have any good ideas/lessons learned/etc.... that may help solve my problem. I used synthetic last oil change, but that was the first since I got the truck. It has 120,000 miles on it. And is there anything else I should look at? Thinking about Seafoam. I have a 98 4.0 SOHC if this helps. Thanks!
-Rog

 

[JohnJ]

A few questions:
What color is the sludge? Do you drive mostly short trips? Has your PCV valve ever been replaced? Are you losing any antifreeze? Does your truck run poorly?

 

[gijoecam]

Indeed, please define 'sludge'.... I find it hard to believe anything mroe than oily foam can accumulate on an oil cap. If, in fact, there is sludge on the oil cap, the rest of the engine is going to look like molasses... I just don't see that happening...

-Joe

 

[4x4Xtreme]

I drive short distances less than 2 miles to work. I replaced my PCV Valve about 2 months ago. Here is what the sludge looks like:

It is not on the oil cap, nor on the threads, it's just below the threads.

 

[Russ in CT]

driving just 2 miles at a time isn't great for the engine. A by-product of fuel combustion is water, and it gets into the exhaust and oil. If the engine fully warms up, it just burns off. If not, it rots exhaust systems and contaminates oil. Since its the same short distance each time, it warms up about the same amount, which means the moisture is always sitting in the same place in the exhaust, rusts that one spot prematurely.

In general, drive it farther at least once a week, and change your oil more frequently.

Moisture in the oil though turns it into a foamy, brown milkshake, not so much the nasty black crud in your photo. Can you peer inside the valve cover opening, is it nasty in there too? What about the dip stick, what does that oil look like?

 

[unclemeat]

Fuel can also contaminate the oil. When you do not allow the engine to operate at normal temperature for at least 15-minutes it will accumulate in the oil.

 

[aldive]

What oil and what oil filter are you using?

 

[biggs92EB]

seafoam.....its a wonderful thing

 

[4x4Xtreme]

I used Castrol GTX High Mileage last time I believe, along with Advanced brand filter, I forgot the name. I think I am going to try the Seafoam though, I keep hearing good things about it. The truck isn't running bad and I'm not losing any coolent. I hope this works, I will probably do a couple oil changes in the next couple of months to kind of flush it out. I should drop the oil pan and see what it looks like. On a SOHC is this hard? I'm sure I can look that up on here though, I find everthing else here, lol.

 

[biggs92EB]

I used Castrol GTX High Mileage last time I believe, along with Advanced brand filter, I forgot the name. I think I am going to try the Seafoam though, I keep hearing good things about it. The truck isn't running bad and I'm not losing any coolent. I hope this works, I will probably do a couple oil changes in the next couple of months to kind of flush it out. I should drop the oil pan and see what it looks like. On a SOHC is this hard? I'm sure I can look that up on here though, I find everthing else here, lol.

Seafoam is a good idea, that sludge will clog up oil passages and starve components in your engine of oil, and then you get the knocka knocka, and thats bad, seafoam it change your oil, run it for a couple thousand miles, seafoam it again, and it should be alright, synthetic oil will not sludge up like non syn. I only know this because i have owned a few Dodge Intrepids, the 2.7 in the dodge intrepid is a sludge *****.

 

[shucker1]

Just a reminder. In the past I have seen guys run crank case cleaners through the engine and all of the "goo" later washes out and clogs up the oil pump pickup screen.

If you do this watch your oil pressure, if it begins to drop off stop before you wipe out a bearing.

 

[4x4Xtreme]

Thanks guys, you've been a big help.

 

[redneck21]

Make sure you do what shucker1 said about ur oil pressure. I would get a oil flush clean seafoarm is ok in the oil but the oil flushes work a lot better.

 

[Daryl Baines]

I changed my oil about 2 months ago, got about 2000 miles on it since. I noticed today while checking things out under the hood that I have a huge sludge buildup just inside the oil cap. Anyone have any good ideas/lessons learned/etc.... that may help solve my problem. I used synthetic last oil change, but that was the first since I got the truck. It has 120,000 miles on it. And is there anything else I should look at? Thinking about Seafoam. I have a 98 4.0 SOHC if this helps. Thanks!
-Rog

My son had a 4.0 with 100K and he also had the same issue I have used Auto-Rx with very good results and gave him a bottle to try and it worked you might want to check it out but you have to order on line not in parts store here is the link Auto-Rx.com hope this helps you out.

 

[Mac Daddy]

I just bought a 97 Explorer with 100K on it with zero oil pressure...

Dropped the pan and there was three inches of solid sludge..... So much the pick up screen was submerged which equals zero oil pressure.

I've read all over the net that this is a common problem with these 4.0's if they are run over 3K on oil changes. What are the thoughts on this forum?

Thanks

 

[ranger7ltr]

Very common...Especially high mileage engines...

When you don't know the maintenance history of the truck slude can build up massively...I bought a 99 Sport with 151k on the clock and the no oil pressure situation was there as well...

I dropped the pan and this was what I found...I cleaned the windage tray, the oil pan, and replaced the pump and pickup...Ran the truck for 20k with excellent oil pressure and still had lots of sludge in the top end even after running synthetic oil for the entire time...Finally replaced the long block and now the engine is sludge free and going to stay that way..

 

[jrowe6]

i took a qt of oil out and replaced with a qt of atf, been running it for almost a week. i dont drive much so im waiting for it to be in there for about 200 miles then im doin an oil change. no more valve clicking, it wasnt bad before, but its 100% gone now.

 

[NHarris]

....Wow..... I'll be checking my 98 for this soon. This count for the 02-05s (4.0) too?

 

[2000StreetRod]

check thermostat

. . .
Dropped the pan and there was three inches of solid sludge..... So much the pick up screen was submerged which equals zero oil pressure. . . .
Thanks

I suggest that you check your thermostat. Some hot climate owners remove their thermostats in an ignorant attempt to solve overheating problems. A thermostat allows an engine to quickly warm up preventing sludge. build up.

 

[tweakedlogic]

We had a Lexus SUV come in wanting a tune up and oil change. We couldn't even add the oil because the sludge was blocking the filler hole. popped off the valve cover and noticed just how bad it really was. We put in a gallon of diesel fuel and 2 qts of ATF. started the motor and let it run for about 30 sec. let it sit for an hour or so and repeated a few times. then drained it and changed the filter, topped off with cheap oil and seafoam. started and let it sit. It took all day for this oil change...
after a few more cycles, we changed the oil and filter again. the top end of the motor looks almost like new.
It's a lot of work, but I suggest you try that.