Best Way To Remove Sludge From Oil Pan?

I think a more important question is 'why' are you getting a sludge buildup in the first place? That is 'not' a normal thing to happen and is usually related to a bad PCV or CCV system. (crankcase vent)

A buildup of sludge is 'best' removed physically by dropping the pan and cleaning it out. Dissolving it will block the oil filter almost instantly which causes the bypass to open so the sludge just pours back into the pan or gets pumped around. This is not good for the engine and could take a dozen or more filter changes to get the oil clean.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:

=== Seafoam originally designed for outboard marine engines, primarily for valves, head. Try auto-rx.com for engine sludge, but surely removing and cleaning the pan is best.

How often are you changing your oil? You may find that you need to accelerate the change interval.

Another question, what car and engine is involved? There have been some engines of certain years that have had unique problems which result in sludging. F.eks, GMs with leaky gaskets or decomposing plastic plenums, certain Hondas and Toyotas, etc.

I made up a pan cleaner that circulates solvent (I use an oil/kerosene mix) through the pan to clear out any crud. It is basically a modified fuel pump that runs through a chunk of line that slides down in the dipstick tube. The end is formed into a dual spray nozzle so it sprays around in the pan pretty good. The pickup tube goes into a large drain pan with a filter on one side to keep the crud out of the pump. Made it using one of those plastic drain pans. Seems to do a good job as long as you turn the tube a couple times so it sprays around the baffle and pan. I tested it on a few dirty pans and my test stand engine so I could see what it did.

I you DISSOLVE the sludge, then it does not cake up on the filter. If you disperse a bunch of crap, then you might have an issue with circulation.

To me, frequent oil changes with good quality oil are the best way to avoid sludge.

If one pulls the pan, then certainly he should clean any filings, magnetic dust, or sludge mechanically.

Take care HLS

..."so it sprays around in the pan pretty good."

I can't see that working real well with the crank and rods in the way.

Crank and rods are not that far down in the pan. The sludge/crud is usually below the baffle. Plus at 60 PSI the solvent still gets around pretty good.

Stoddard solvent works BUT it can damage some types of bearing material. So I stick with the Kero/Oil mix. It dissolves the crud and by keeping it flowing through the pan it also washes out any loose crud.

I have run engines with the mix in them if they are REALLY sludged up. But if they are that bad I'd rather pull the rocker covers, intake and pan and clean it manually.

As others have said, dropping the pan is best. But I have done other things....

About 6-8 years ago, my father had a 200,000+ mile farm truck (92 Dodge Dakota, 5.2 Magnum/automatic) that would lose oil pressure at random. We dropped the pan and found about 2" of gritty, hardened, broken down sludgy junk in the pan and the entire inside of the engine coated with more. Yet the thing ran fine and didn't even burn oil. Figuring that we couldn't lose, we cleaned the pan, put in a new oil pump (the rotors on the old one were ground down amazingly), re-installed the pan, and then attacked the rest of the crap by running many gallons of Kerosene down each oil fill pipe (one on each valve cover) to rinse down the rest of the engine. 5 gallons down one valvecover, catch it out the bottom of the pan, filter it through shop rags, and then pour it down the other valve cover. We repeated the process about 5 times until no more junk was coming out the pan.

Then to re-coat everything with oil, we filled it with an absurd amount (about 8 quarts down each valve cover) of the cheapest non-detergent oil we could find- then drained that (never starting the engine) and kept in a drum to use as chainsaw bar oil. Re-filled it with a better grade of oil than he'd been using, and fired it up. Changed the oil filter about

3 times during the first 2 hours of operation, changed the oil again, and tried to forget what the insides had looked like. We expected to get maybe another few thousand miles and a year or two out of it... but being a typically indestructible Mopar 318 it had other ideas and is *still* running to this day and bumping up against 300,000 miles. I think Dad still has a lifetime supply of non-detergent chainsaw bar oil... :-)

Why do you want to remove the sludge? It will remain benignly in place unless someone thins it out with a solvent. Seafoam is only the latest of several commerccial and home "cures" for engine sludge. Unless you want to remove all of the sludge by disasssembly and clenaing my recommendation would be to leave it alone.

By chemically loosening up all that solidified gunk you run an excellent chance of plugging an oil hole somewhere. One of those cleaners will create the impression of a job well done with lots of black goo and chunks flowing out. Remaining unseen but of concern is all the stuff that was loosened but not evacuated.

The last time I cleaned out an old nasty oil pan, I used some gasoline.It worked for me. cuhulin