• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

black/brown sludge on my rocker arms


Surrey

Well-Known Member
Joined
Jan 12, 2011
Messages
1,800
City
Vancouver, Canada
Vehicle Year
1989
Transmission
Automatic
I just pulled my valve cover to replace the gasket because my engine is a oil-covered mess... And I found lots of thick brown sludge over everything. Its all between the springs, on the bolts, everything...

Any idea wtf it is? I was thinking previous owner was trying to use some of that stop leak crap in the oil?







Any idea what I can do to clean it up? Just wipe it with a cloth? Blast it with brake clean?

Is this crap gonna toast my engine?
 
Last edited:
pulled the drivers side valve cover... Same thing. thick brown sludge over everything.
 
Could just be from running too long between oil changes.
Once its there it doesn't go away, so it could have been there since you bought the truck.
Clean it out and check it in a few months.

PCV valve helps to minimize this, also the Vent tube to the air plenum, these need to be cleaned at each oil change.


How are your valve guide seals?
You burning oil?
The exhaust seals can dry out and leak hot exhaust this can crystallize the oil vapor in the valve covers.
Failing Intake valve seals tend to allow oil to be sucked from the valve cover into the intake and burned, failing exhaust seals are the opposite positive pressure in the exhaust manifold pushes exhaust gas into the valve cover.
Piston ring blow-by can do the same only usually in the crankcase area.
 
The outside of the engine is very dirty, and the dummy gauge for oil pressure shows low/nothing until you step on the throttle, at which point it goes up to normal. Could that be related?


Whats the best method for cleaning that stuff out?
 
You could have some sludge in the oil pan, oil pick up might be getting clogged up, or it could be sludge in the oil pressure sender, causing it to read low, you can unscrew it and check.
Before you change the oil the next time put a 1/2 quart of ATF in the engine and drive it a few days, ATF is a high detergent oil so helps clean stuff out, like oil passages and lifters.


For cleaning, First.....block off the oil return holes, some rags work well, don't want that junk in the oil pan.

Then more rags and elbow grease, when you have the big stuff out spray a little degreaser on a rag and wipe.

OR

Remove the heads and have them hot tanked :)

But cleaning them by hand is just fine.
 
Last edited:
You could have some sludge in the oil pan, oil pick up might be getting clogged up, or it could be sludge in the oil pressure sender, causing it to read low, you can unscrew it and check.
Before you change the oil the next time put a 1/2 quart of ATF in the engine and drive it a few days, ATF is a high detergent oil so helps clean stuff out, like oil passages and lifters.

its not a daily driver, so if I was to take it out for a long drive to get that atf circling through, how long should I go?

Also can anyone else comment on this method?
 
I've used the ATF trick plenty of times. I've even run a quart of ATF for 4K miles between oil changes. Never had a problem, but I'm sure there are better flush additives on the market.

The only thing I worry about when its that dirty is the sludge breaking off in chunks and clogging the oil pump pickup screen.
 
Last edited:
Is this a better method for cleaning than say one of those store-bought engine flushes?

I have no problems throwing $10 at a can of seafoam or something else if it'll help...
 
ATF,Seafoam and the other things work...but that's a LOT of sludge :( Like they said, ya don't want this crap breaking loose and circulating (like blood clots in blood). Being a "Redneck" I was taught if a motor looks like that and you don't have the cash to fix it right.....don't disturb it (the sludge or carbon). I knew one guy who used a pressure washer to clean out the top end...he said it ran fine....I doubt for long though lol
 
Well its a 2.9 so there is no way I'm spendin a bunch of money or time to tear the whole engine down to clean properly... when it dies a4.0 shall replace it.

That being said what are my best options for cleaning this? I was thinking a toothbrush, some atf, and a pile of rags...

Anything else I should be checking for sludge? Like pull the oil pan or check the sending unit or somethin? I'm not really sure where to go from here
 
IMHO, dont fix if aint broke. If its running ok i'd say let it be, But if you really want to try and clean it up (i wouldn't blame ya) I'd say take off all the parts you can like the covers, sensor, sending unit, and anything and everything you can get to and clean them by hand. And then on the long block plug up or block whatever oil passages you can with rags, tape, cardboard, rubber plugs, anything and everything and then get at it with picks, scrapers, brushes, shop vac, or anything and everything you have to clean it with, and then dont forget to remove whatever you used to block the oil passages!
And depending on how anal you are...
(*OPTIONAL*) And not needed but I guess If you were "REALLY BOUT IT" you could take off the rocker arm pedestal and give that a good cleaning and that would give you more room on the top of the head to clean.
(*REALLY OPTIONAL*) And really not needed but you could drop the pan and get inside it and the pickup screen but you might have to be a contortionist to get in there as you cant really drop the pan out of the truck (that's a whole different story).
 
Last edited:
take off all the parts you can like the covers, sensor, sending unit, and anything and everything you can get to and clean them by hand.

Can you elaborate on what is accessible/cleanable?

There is so much gunk I can't even tell where the oil passages are, so I know Im going to end up pushing some of this crap down into them as I go... Suggestions for dealing with that? Im thinking I might need to go get a suction gun?
 
The only thing I worry about when its that dirty is the sludge breaking off in chunks and clogging the oil pump pickup screen.

That is why you get it good and hot, drain the oil, fill it with diesel, and let it sit overnight.
 
Last edited:
That is why you get it good and hot, drain the oil, fill it with diesel, and let is sit overnight.

fill the crank case with diesel?

And this will break down all the sludge in the oil pan, or...?

Please elaborate, this sounds like it could be useful.
 
Diesel fuel is full of detergents. You get sludge in stuff like the oil pan and dump diesel fuel in there it helps break down the sludge and remove some of the varnish. It's not thick enough to run the engine with though.
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top