LouW

I have frequently read in the forums that a good way to clean a gunked up engine is simmer overnight in a crock pot filled with anti freeze. Today I bought a 1 1/2 quart crock pot at Wal Mart for $6.00. It is the perfect size for "cooking" engines up to about .60 size. Just thought y'all would like to know

caz

Was an article in one of the mags on this, I don't remember which. Said remove all non metal parts and take back plate off.Puy on low for 4 hours. Works well on mufflers also.Lubricate with after run oil when done. Save anti-freeze for reuse. Do Not use crock pot for food. Works really good,even on mufflers.

JKovats

My Feedback: (2)

I have done this with many engines. Remove the carb . Cook for about 2 hours and start checking. Some come clean in 2 hours, some 4-5 hours. Wouldn't leave it overnight. Remove the glow plug and turn it over a few times submerged whrn you first put it in. Careful when you remove the engine from the hot antifreeze.. It is really hot and retains the temperature for a long time. Shake out anti freeze, add afterrun or marvel mystery oil. Will look and run like new.

John

Geistware

My Feedback: (16)

I have never tried After run oil but WD-40 to clean out the dislodged particles and then marvel mystery oil to lubricate.

MR Flyer57

I have just gotten into this, and have tried a few different ideas.

I have found that taking the engine apart is the best way. I disassemble it as far as possible, but at least take the back plate off and the head off.
If you can pull the crank even better. I then take all the little parts and put them in a little stainless cup, fill it with prestone antifreeze and put that into the crock pot full of antifreeze.
I cook it on high for at least two hrs. and up to 4 hrs. I then pull out the stainless cup, drain all the antifreeze out into the crock pot as I can, and then take it to the sink and flush with water.
After it has cooled down, which takes just a second, I get a tooth brush and brush the parts under the running water (remember to screen the drain). Sometimes I will use a little soap if it looks like there is a little oil film still on the parts. Just look at the brush and you can tell if you need a little dish soap on the work.
If the parts are not coming clean with just a little brushing they need a little more cooking, so back they go for another two hrs. This rarely happens and is mostly the heads which seem to suffer no ill effects even if left for a long time in the crock pot.
The parts come out like new, and I mean really like new. It is really remarkable.

Problems can occur!! One thing I have found is that anodized parts suffer, and so do plastic parts, such as the plastic housings found on Cox TDs. The paint on your old green head will be gone also, so if you use this method you will have to repaint it.
I also do not use this process on carbs or glow plugs. Although it will work on all metel parts, I have found that the rubber and gasket parts on carbs can be at risk, also the carbs don't usually have fuel cooked on and can be cleaned with fuel and then soap and water.
The glow plugs probably could be cleaned, but at $5 apiece why take a chance.

After the cleaning you have a unprotected engine and all the parts need a coating of oil. Some use WD40 to displace water, but I just blow them out with compressed air and oil them. but them together and test fire them. It will warm them up and get rid of all the water. I then add after run oil and put them into zip lock bags.
You could also heat them with a blower, like the one used to shrink monokote, and dry them to store as extra parts.

I have found that if you don't take the engine apart (at least the head/glow plug and back plate, that a lot of junk gets left in the engine no mater what kind of flushing you do. If you don't get the sleeve and piston out, you must really flush out the block and make sure nothing gets left there.

You can use the antifreeze until it looks so dirty you can't imagain it working, and then it is off to the recycle bin. I did all the engines so far in one bath of antifreeze and have a half gallon left.

I have had a great time cleaning my collection, and I started with the most hopeless of the bunch. Man did they look good after the bath.
Good luck
MR Flyer57

J_R

MR Flyer57

Nice report.



Let me add a couple of things. I use a large tea strainer with the handle removed to put small parts in.

Some folks have tried it without heat. It does not work. Environmentally safe antifreeze does not work. It must be the ethylene glycol based stuff.

I use the low heat. I will let the parts cook overnight. High heat is OK for a short period. If you use high heat, over an extended period, it will discolor the aluminum. That seems to have no long term effect on running, but makes the engine look funny. I have left really stubborn engines in the pot for as much as 5 days. The antifreeze eventually dissolves the crud without the toothbrush. I prefer the toothbrush to speed the process. I have found that it will not remove the carbon on the top of the piston, regardless of how long the piston is cooked.

As you said, there are some plastic parts it will attack, and notably, it should not be used on YS engines unless they are torn down and all the gaskets, etc removed. YS uses a different material than most other manufacturers.

If we think about what antifreeze is really used for.. a car, to keep the cooling system clean, while running through gaskets, seals, and even plastic radiators, at about 220 degrees F, we can see that, in most cases, it will not harm the parts of our engines. It can even be left in the engines for a few days without damage. That's nice because it allows us to, rinse the engine, assemble it, and take the engine to where we can run it later and do no harm.

You can tell when it is time to change the antifreeze in the pot. It works slower and slower.

The stuff is poisonus and so are the vapors, over extended periods. Short periods of exposure are OK. The vapors are sweet smelling and attract kids and animals. Keep them away from it. Do not use this process indoors, use it where there is good ventilation. Keep the lid on the pot when your cooking. Never again use the pot for food, the stuff gets into the pours of the pot and it is almost impossible to get it out.

JR

Stripes

My Feedback: (19)

Well in a car engine the antifreeze never touches the bearings, piston or crank. Even in the water pump the bearings are isolated from antifreeze. In fact it is a seal leak into the bearings that washes out the grease they run in that causes the failure of the waterpump. Traditional green antifreeze deposits, over time, silicates on the inside surfaces of the cooling system. You can see them when you disassemble a car engine and the inside of the cooling system has a distinct color.

Now I am totally unsure of the amount of silicates that would accumulate in just a few hours or days immersion. It must not be much if any because a lot of model engines seem to have received this cleaning and must function well or their owners would be screaming.

J_R

Hi Stripes

Well, you sent me digging. The chemical formula for ethylene glycol is C2H6O2. I can not see where any silicates are going to come from. I did run into some information that would lead one to believe that when antifreeze is mixed with tap water, as we do in cars, that carbonates are a virtual certainty. This would have about zero effect on cleaning engines, since we don't mix water with the antifreeze, except to rinse the parts off. Still.. it has been a long time since I took chemistry, and if silicates are a real possibility, I would be interested in knowing more.

Since we do not use antifreeze, except as a solvent, for our purposes, I doubt that the fact that it cleans bearings is of any importance. I guess we just need sure to get as much of the rinse water out and lube the heck out of things to insure the bearings, etc, don't rust.

JR

Stripes

My Feedback: (19)

Well take it from me that the silicates are there probably part of the additive package. Silicates are the reason why it does one no good to change a car from the green antifreeze to Dexcool, which is the orange stuff by Texaco and GM. Once the inside of the cooling system is coated with silicates then regular changes of antifreeze are required and the long life virtues of Dexcool are lost because you have to change it anyway just like the green stuff.
Changing antifreeze in cars is to replace the anti-oxidative additive package not the glycol base material which is essentially unaffected by age I believe. So the fact that your antifreeze wears out with use seems to indicate that it is one of the components of the additive package that is doing the cleaning.

J_R

Thanks Stripes

It looks like I will keep doing what I am doing.. with my cars and with my engines

JR

jessiej

Excelent point, JR. This stuff is DEADLY, even in tiny amounts and is attractive to kids and animals. It causes irreversable and fatal kidney damage very quickly.

BE CAREFULL!

J

Stripes

My Feedback: (19)

Inquiring minds want to know so I asked a GM engineer whose speciality is engine cooling. I sort of view what he says as the voice from Olympus. He sees it as OK to do. Here is his reply:


Honestly I do not know the answer to your questions. I would not expect the silicates to be doing anything harmful to the engines...based on the fact that they seem to run OK after doing this to them I assume this is kind of a moot point. I don't know what in the additive package would have a cleaning effect like you observe. I suspect the ethylene-glycol is dissolving the crud and it just becomes saturated with whatever compound the crud is made of and then it will not "clean" anymore....Kind of like trying to clean salt off of something with saturated salt water...it would not dissolve anymore salt but would not necessarily be "worn out". I think that the fresh ethylene-glycol just dissolves more stuff. The family of glycols can be fairly aggressive solvents ... brake fluid is a glycol and you know what it does to some paints. Maybe fresh brake fluid would be a good substitute cleaner. Or, you could try the same experiment with DexCool and see if it cleans the same. If it did then it obviously wouldn't be the silicates as there are none in DexCool and it is still an ethylene-glycol coolant.

J_R

Thanks Stripes

Hmm. I think I will stick with the antifreeze. I have seen what brake fluid does to a car finish, and that was at room temp. Since I do this in the garage, and occassionally, the antifreeze splashes when a part is accidently dropped back in, I would rather not risk the car finish, or anything else for that matter.

I think your friend is exactly right about the antifreeze becoming saturated with crud. It becomes pretty obvious, as it becomes saturated, that it is time to change it for fresh.

I still have no idea why it turns the metal darker gray when the temperature is turned up for an extended time.

In any case, it sure works well on model engines.

rc-sport

My Feedback: (12)

Ok guys, I have 2 4 stroke engines that could use a good cleaning, a Saito and an OS. What should I remove from the engines before I cook them?

prop_nut

several years ago there used to be a product called Z-BEST engine cleaner, don't know if it's still around, but it really worked well. You brushed it on and let it sit for bit, little brushing, then rinse with water......work really well.

bentgear

It is the ethylene glycol that does the cleaning. If you had a source for the real stuff you could use that and not have to worry aboutthe additives in the antifreeze. I don't worry about them anyway. Not enuff time in the pot for them to cause a problem.

Ethylene glycol will kill dogs, cats, humans, etc. but it is much safer than some of the things people have used to clean engines. If ingesting a few drops or breathing small amounts of vapor would kill you then every mechanic I know would have been dead a long time ago. I am not saying that it is safe, just don't drink it or stick your head over the pot and breath the vapors for an extended period.

Love the way it leaves mufflers looking after a slow cook overnight.

Ed M.

Lee Belew

My Feedback: (2)

In an earlier post someone made the comment that this method would not clean the top of pistons. I would like to submit the following photos. One piston has not been cleaned the other one has. The two pistons looked the same way before cleaning. In fact the clean piston had a stuck ring before cleaning. The engine had really been over heated. I had to pry the ring loose after cleaning.

Lee

Ed Smith

To be on the safe side, anything that is not metal.

Ed S

martyg

My Feedback: (42)

Will the crock pot method also strip the carbon off 4-stroke valves?
Or do I still need to chisel and scrape?

Ed Smith

You should not have to chisel and scrape. The carbon should be soft enough to be removed with fine steel wool or scotchbrite.

Ed S

nedyob

My Feedback: (67)

I have a question pertaining to the Crock Pot cleaning mithod. I recently aquired a ASP 91 2 cycle engine for about $5.00 (found it at a local garage sale)
The engine looked as tho it had been spent a long time in a in a corn field. It was so clogged with dirt and sand that the crank wouldn't even turn.
I went out and bought a crock pot and a jug of antifreeze, stuck the engine in the crock pot for about 12 hours after taking the back plate, carb and muffler off.
The engine came out a grayish color, but the engine crank turns a heck of alot better. Only thing is when the it seems the bearings may still have gritt in them, and the counter waight on the crank shaft & bearing still has a brownish residue (it may be rust)
Should I just throw the engine back in for a longer period of time, or is the engine shot.
I guess I would like to bring the engine back to life, and can't resist the challenge to try.
Let me know some on your expiriences.
NEDYOB

thexfiles

My Feedback: (7)

i'm going to add a new question to this debate:
last summer i dropped an os max 40fp into a farmer's field.
we could not find it until he harvested in the fall.
the plane was totalled but the engine was buried in the dirt and after i washed it and reassembled it it ran beautifully.
only one problem:

the outside of the engine is stained black where water and the various elements in the top soil had come in contact with the crankcase and muffler.

will the crock pot and antifreeze work on this discoloration?

J_R

Hi Lee

Did you use anything other than antifreeze to get the carbon off? If a brush, what kind? How long did you cook it? What temp on the crock pot?

LOL, tell all.

JR

Lee Belew

My Feedback: (2)

J_R

I used a denture type tooth brush and on some places I used a cotton swab and acetone.

I left the parts in the anti freeze for two night and one day. No discoloration.

Just a note: The pistons are from a Ryobi engine and all of the crud was accumulated in the Weedeater configuration.

I have 7 of these that I am cleaning up and they all look very good.

Happy flying

Lee

Ed Smith

The crockpot cleaning method is great for removing burnt on fuel residue. If the engine is just a blob of mud and grit then clean all that off first. The antifreeze will not remove grit from bearings. The engine should be taken apart before cleaning. If left assembled even loose bits of residue can get into bearings. Other than burnt on residue all other dirt can be washed off without the need for soaking in hot antifreeze.

Ed S