De sludging motor

[SnowDrifter]

Let me preface this by saying this is purely hypothetical. I'm just curious


So... I hear a lot about sludge removal. How once it builds up, it needs to be mechanically removed. However... I was thinking.. Would it be possible to re-dissolve it somehow? By frequency OCIs or something? Or is it one of those things where once the reaction has taken place there's no reversing it?

 

[Shannow]

It's entirely possible in theory.

In industry it is done regularly, by installing three basic technologies
* Electrostatic separators, they collect sludge/varnish particles, and remove them from the oil.
* Ion exchange mechanisms (use the same principal as water deionisers to collect sludge/varnish
* cellulose depth media, sidestream oil has varnish/sludge removed.

When the oil is entirely free, it starts to pick back up sludge/varnish from deposits that have already laid down, and over time will clean systems up.

In theory, same is possible in engines.

I had an electrostatics guy trying to sell me a turbine set-up the other day, and I asked him wouldit be possible to scale down to engine sized...would probably be the size of a drink cooler, and cost thousands.

I've had thoughts about putting a cooling system on the oil filter, to try to get the varnish to collect on the metal surface, putting a sidestream cooler like an AC condesner to get it below the temperature at which it could be filtered.

Have tried 600 mile oil changes for a couple thousand miles, and seen no change in my varnish...theory being that the new oil will saturate out quickly, picking up what's there, before it starts to lay down it's own.

 

[901Memphis]

There's no problem with dissolving it, you can use solvents. The problem comes when you quickly release said buildup too quickly, you run the risk of plugging the oil filter, running into bypass and plugging either the oil pickup screen or a oil drain hole.


Depending on the amount of sludge your best bet is frequently changing the filter and keeping the oil changed at shorter than normal intervals. The oil should be good for at least half of the severe service in a sludged engine, but filters can load fast.

Filter cutters come in handy for this purpose to inspect and compare filter loafing.

 

[Lapham3]

Interesting theory that today with vastly improved oils and fuel injection sound good. Years ago I've done the old kero/diesel oil change out idling under no load and the amount of gook drained could be amazing. This where maint appeared iffy and northern cars with the condensation likely not burned off because of short trip use. Going thru such engines the valve covers + pans could have 1/2" buildup-enough to displace a quart of oil. The only practical way to start dealing with such was mechanical means and I'm talking a putty knife-then there were the likely wear issues to deal with. Unless a vehicle had use beyond severe and under maintained I haven't seen todays cars get to any levels approaching this. As Memphis says-frequent oil/filter changes. Dan Mpls. Mn.

 

[Donald]

Originally Posted By: SnowDrifter
Let me preface this by saying this is purely hypothetical. I'm just curious


So... I hear a lot about sludge removal. How once it builds up, it needs to be mechanically removed. However... I was thinking.. Would it be possible to re-dissolve it somehow? By frequency OCIs or something? Or is it one of those things where once the reaction has taken place there's no reversing it?


The first is to verify the engine really has sludge. I think using a synthetic oil and 3K or 5K OCI (maybe start at 3K then 4K then 5K) will start you on a downward trend.

If an engine is running fine even if it has some sludge as long as you make the sludge trend downward you will be fine.

I would assume if you pulled the valve covers from various engines in the boneyard many will have sludge but they are in the boneyard due to rusting or accident or transmission.

 

[bigt61]

If it has serious sludge, I wouldn't start with or ever use synthetic. I'd do a few short interval changes (1-2K) with the cheapest dino and filter you can find. Then gradually extend to 3k OCI - monitor - and eventually work up to 5-6k with a quality blend. Do not use de-sludge additives. Slow and steady.

 

[punisher]

Whatever happened to "Auto-Rx"? I remember years ago it was referred to/advertised fairly heavily on this forum.

 

[Greasymechtech]

SN/GF5 oils will clean sludge. Shorten the interval.
Detergents, solvents, esters, synthetics, HM oils, ...can also be used but cost needs to be considered.

Regimen is all that is needed.

 

[tommygunn]

How about something like Motor Medic ?

Or Napa Mac's Fast Flush ?

There's also Kreen.

These have been out for quite some time.

 

[Donald]

Originally Posted By: punisher
Whatever happened to "Auto-Rx"? I remember years ago it was referred to/advertised fairly heavily on this forum.


Auto-Rx is still around. I believe it will work on some types of sludge and you need to follow the instructions. I am sure you can find it on the internet. Its also good for transmissions.

There is also Kreen.

I do not think there is one type of sludge nor one method to remove sludge.

But slow goes it. Forget the flush.

 

[DoubleWasp]

Doing any kind of fast-flush at idle is a waste of time, because the oil isn't going to find its way to nearly as many places as it will at higher rpms.

With most pushrod engines, you can pretty much run the engine with no valve covers on at idle, and very little is going to escape the engine. Do the same thing at 2500 rpm, and it will shower the globe in oil.

The higher rpms are necessary to really get the detergents where they need to be.