Best way to remove sludge?

[Dave Sherman]

From what I gather, Auto-RX seems to be the favorite. Are there any other ways that seem to work, short of actually scraping it off?

I have a '77 MG Midget, and there seems to be some gunk on the cylinder head under the rocker arms for #2 and #3. I don't know much about how the P.O. took care of it (not great, from what I've seen). Is it best to clean it up somehow, or don't worry about it?

 

[JohnBrowning]

All of the other stuff is solvent based and would be risky in an old possable sludged up engine! AUto-Rx has no solvents in it at all and is going to clean things very gently. The problem with strong solvents for sludge removal is that you have no idea how big the pieces will be that break off. You have no idea if the solvents will damage your old seals. You have no idea if the solvents are going to work long enough to disolve all of the sludge before they boil off from engine heat and get dumped out the breather/pcv.Solvent based flush's work best in vechiles that really do not need that much cleaning and are realatively healthy! Auto-Rx is a slow proccess and you would have to put some miles on the MG in order for it to do it's thing but it is the best product for this application!!!

The only alternative I would ever consider on this application would be Lube Control. I would only consider LC though if this car was going to be a daily driver becasue LC is not designed to be a sludge remover it would take a year or more of oil changes and useing LC to get all of this sludge out of the engine!

 

[Dave Sherman]

Thank you, John. I'm thinking I might see what I can do with some careful scraping first, since it sounds like the Auto RX might take a year or more for the amount I drive it. Thanks for the info, I appreciate it.

 

[BrianWC]

FWIW, if the sludge is not in a spot that sees a lot of oil flow, arx may leave it alone. I have some in my valve train area like that that didn't really go away after arx. Just be careful if you do go another route.

 

[deven]

you can try seafoam

 

[Lonnie]

If you can see it you might want to scrape it off and then try the Auto-RX.

 

[BigAl]

I once de-sludged a head still on an engine with a screwdriver and a shop vac. It looked pretty good when I was done. I had to keep the vac nozzle pretty close to the scraping to keep crumbs from falling into the crankcase. That was a long time ago. I wouldn't do it again.

With modern oil I don't see much sludge anymore.

 

[punisher]

Our dealership took in a Lexus or high end Toyota (cannot remember which) in on a trade in one time. During the UCI the tech found a small engine knock/piston slap and when he tried to drain the oil it came out in a nice thick chunky glob. The car only had about 30K miles on it so it was still under Toy/Lexus factory warranty. Our service manager being the evil SOB he was had a tech pull the valve covers and oil pan to have a look around. It was packed completely full of black sludge except for the areas that the cam and valves moved, nasty. The oil pan in the same bad shape with the oil pickup mostly clogged by chunky gunk.

In an inspired bit of evil the service manager had a make ready guy cover and mask the underhood with plastic and use a 4000 psi pressure washer to scour internal surfaces of the heads. The car was then put on a lift and the crankcase was cleaned as well. The engine was reassembled, and it was clean inside, really really clean inside. Oil was added and the engine run until warmed up, and the car was driven to the Toy dealership for what eventually became a new engine, under warranty.

Dealers, we even do it to each other.