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Gelatinous Chunks in Antifreeze/Coolant Change

JSM

Member III
Took the cap off of my coolant reservoir yesterday and discovered that the green antifreeze was loaded with small clear gelatinous chunks. We purchased the boat last spring and have not added any thing to the cooling system. I have no idea how old the coolant is and plan on draining and flushing the system. Is this something that happens to antifreeze as it ages ?
 
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frick

Member III
Did a quick search on this issue

Took the cap off of my coolant reservoir yesterday and discovered that the green antifreeze was loaded with small clear gelatinous chunks. We purchased the boat last spring and have not added any thing to the cooling system. I have no idea how old the coolant is and plan on draining and flushing the system. Is this something that happens to antifreeze as it ages ?

It seems that there is a silica fall out from Dex style antifreeze that can cause this.
It can also happen is two different style of antifreeze are mixed... for example... The Coolant is drained and changed, but a differnt sytle antifreeze is use, and the block was not flushed... the interaction will cause the gelling. Also oil in the coolant will cause this as well.

Here is a quote from a expert...

when you switch to dex cool you usually have to flush the system WELL..as in fill with water....run to operating temp....drain and repeat at least once more (this is to flush the heater core also).

if you just drain and fill there was enough green coolant left to GEL with the dex cool.

its usually not a good idea to change coolant with a veh that was run with green coolant. the dexcool has some issues also.

your better off flushing system with the directions above 2x...then refill with green coolant and hope you get everything out. .


The only solution is to completely flush your system... some recommend using citrus acid for the flush....

Hope this helps
rick+
 

JSM

Member III
Thanks Rick, doesn't appear to be any oil in the coolant. The coolant is green and the "chunks" are small and clear. Just read that Prestone will gell when it gets old.
Engine ran fine last fall before we hauled out for the winter. Will flush and refill.
Anyone have a tips for flushing?
 

footrope

Contributing Partner
Blogs Author
Remove thermostat, use appropriate sized hoses, 5 gallon bucket

This is the setup I use to flush my cooling system. The thermostat has to be removed. I don't do it with a super hot engine, but it works cold and after idling long enough to open the thermostat. Most hose "squirters" have a threaded nozzle and the adapters are available at marine and hardware stores. Utility water pressure at the hose can be pretty high, so regulate the flow to get a thorough flush. Oh, put the radiator cap on tight. I learned that the hard way.

20160916_164046-small.jpg

Edit: Added the "before" picture of the engine in normal running mode so you can see where the black hose usually connects between the thermostat housing and the cooling jacket/exhaust manifold. Different installation variations and model years of these Universal engines may not be plumbed the same way.

20160801_153855-small.jpg
 
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JSM

Member III
Thanks Footrope ! Your post about your head dilemma was the first to come up when I did a search for "cooling system flush".
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Coolant Notes

FWIW, our mechanic has a coolant replacement kit he put together. 12 volt pump with clip leads, a five gallons bucket, some hoses...
Last time he replaced all of our coolant mixture with new, this setup did it without leaving any air pockets in the engine like there would be if we did it by draining thru taps and plugs. Pretty nifty, actually, and time (and $) were minimal.

Also, last time we changed it out, we abandoned the pricy Sierra brand antifreeze with its promise of non-toxicity.
After consultation, we went back to conventional coolant and just figured that if the loop in the hot water tank every gets a pinhole leak, we would notice the awful taste and desist from drinking it.

YMMV.

Loren
 

toddster

Curator of Broken Parts
Blogs Author
Actually the taste is quite sweet. Which is why we have the notorious problem of pet poisoning from antifreeze.

If you look carefully around the antifreeze shelves at the parts store, there are probably a few products to use when flushing the cooling system. Somewhere on the Moyer site, there are detailed instructions for using swimming pool muriatic acid (HCl) to flush the Atomic Four, but the same sequence could probably be used for any engine.

And if you find that you really, really enjoy spending days purging and burping cooling systems, go right to Craigslist and buy yourself an old BMW! :rolleyes:
 

JSM

Member III
Found this at http://downeasteryachts.com/info-index/engine/universal-engine-info.

SUBJECT: Diesel Marine Engine Antifreeze “Gel” Formation
Many automotive antifreeze products contain high amounts of silicate
designed to protect aluminum engine parts and aluminum radiators from
corrosion. When antifreeze is not mixed with fresh water in the correct
mixture (1:1), or changed regularly(usually about every 3 years) it can
cause the silicates to drop out rapidly and create a gel condition which can
block the water jackets and heat exchanger… causing severe overheating. The prevention of antifreeze gel formation is to use the correct,
brand-name, regular life (green) antifreeze in the correct mixture with
clean, fresh water, and change it regularly according to the engine
maintenance manual specifications.
Removing the gel formation from engine water jackets is difficult. Heat
exchangers and engine water jackets must be flushed with a caustic solution,
not water.
 

toddster

Curator of Broken Parts
Blogs Author
Well, that's true that silicates are soluble in basic solution and insoluble in acid. Just the opposite of the case for metals. Maybe a good idea to read the labels of several of those radiator flush products to try to figure out the differences. (BTW: This is the same reason that one uses acidic cleaners like "Barkeepers Friend" on glass cooktops, and not ordinary soaps, which are basic, and could etch hot glass.)

So with an excess of silica, an acid flush might just speed up formation of clay coatings inside the system. Or given the amount of rust and scale that might be lurking in some of these old engines, some really interesting mineralogy might be going on... Perhaps Ericsonite is just waiting to be discovered?
 

Emerald

Moderator
[snip] The prevention of antifreeze gel formation is to use the correct,
brand-name, regular life (green) antifreeze in the correct mixture with
clean, fresh water, [snip]

I would just add to use distilled water to avoid minerals etc. that may be in your local water supply.
 

JSM

Member III
Thanks All, really appreciate all the helpful responses . We purchased this boat last spring. The coolant was probably the only fluid on the boat that I did not change. It was nice and green and at the right levels. Our previous boat of thirty years had a raw water cooled Atomic 4. Dealing with a freshwater cooled diesel is a whole new ball game.
The previous owners were getting up in years and as we get to know the boat I'm beginning to see a lot of "delayed maintenance". Wouldn't surprise me if this is the original coolant.
 

footrope

Contributing Partner
Blogs Author
I edited my post #4 to show the normal running mode of my 5432 engine and to help clarify the hose connections. Your engine could be plumbed differently due to installation differences, whether a water heater is present, or due to newer or older versions of an engine. Or you may have a different model of the Universal diesel. Consult your mechanic if you have doubts about your particular engine.

I don't recommend doing this on a hot engine because the flush is rapid (30 seconds or less) even at relatively low flow rates. You don't want to "shock" cool the engine. So, do this on a cold engine or after a short run if you're using a flushing solution, and there shouldn't be any problem.
 

JSM

Member III
Thanks Craig, the pics help. My set up is a bit different, Its an M25xp with a water heater. When flushing a cold engine is it necessary to remove the thermostat ? Also how important is it (if at all) to flush in the normal direction of coolant flow.
As of now my boat is on the hard, the fuel tank is out and the yard has yet to turn on power and water.
My plan for this weekend is to suck all the coolant out of the reservoir and expansion tank with a vacuum pump, remove and replace all of the old/original hoses as well as removing the heat exchanger to get a look at the inside of it.
On these heat exchangers, does the coolant run thru the interior tubes or is it the water?
Thanks
 

footrope

Contributing Partner
Blogs Author
Thanks Craig, the pics help. My set up is a bit different, Its an M25xp with a water heater. When flushing a cold engine is it necessary to remove the thermostat ? Also how important is it (if at all) to flush in the normal direction of coolant flow.
As of now my boat is on the hard, the fuel tank is out and the yard has yet to turn on power and water.
My plan for this weekend is to suck all the coolant out of the reservoir and expansion tank with a vacuum pump, remove and replace all of the old/original hoses as well as removing the heat exchanger to get a look at the inside of it.
On these heat exchangers, does the coolant run thru the interior tubes or is it the water?
Thanks

That sounds like a good plan. It is absolutely necessary to remove the thermostat. Plan on getting a new paper gasket for re-assembly. When the engine is cold the thermostat is closed and therefore there would be no flow in some sections of the cooling system. Even with a warm engine the thermostat will close when cool water flows past. If I don't remove the thermostat I get no flow at all because the flush connection is going right to the top of the thermostat.

I have flushed in both directions and I don't think it makes a whole lot of difference. The pictures I included show flushing in the opposite direction of normal coolant flow. The picture shows the easiest way to connect the hoses on my engine.

I don't know the exact plumbing of the internal passages of the heat exchanger (HX). The chunks could cause some blockage if they're numerous or large, so it is a good idea to remove it and open up the end caps. Replace the pencil zinc, too, before putting it back on the engine. You can probably connect the coolant loop hoses with a hose union for flushing the rest of the system.

The coolant loop of the heat exchanger on my setup is a pair of right angle ports that are recessed from the end caps. At one end are the sea water inlet and outlet ports and those connections come straight out of the exchanger at an angle to each other. The four hoses are easy to trace if you can get a look at the connections and follow your raw water and coolant hoses. Inside the HX here are usually a few tubes that are blocked permanently on one end, so be gentle if you probe the tubes. A radiator shop can boil out the heat exchanger.

Craig
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
Craig,

Uh, after flushing with water, how do you get the water out so as to add the new coolant?

Never did this, and it's time.
 

footrope

Contributing Partner
Blogs Author
The rest of the story

Believe it or not you can blow out close to a gallon of the water with your lungs. But not all of it. You could also adapt a dinghy inflator or any kind of low pressure air pump, or suck some out with a wet/dry shop vac. Now that I think about it, to get the last quart out before I put coolant in mine, I used a basketball pump and duct tape for a reasonable seal.

When you fill, pour the coolant and/or water into the thermostat housing also. That will help prime the water pump and will speed up the fill. If you just fill the cooling jacket you not may get much water into the block. This is especially true if the water heater is connected to the water jacket.


My cooling system capacity is about 2 gallons, or maybe slightly more with the water heater. I get a fresh bucket and blow out about a gallon and call it good. I just use tap water rather than distilled water. I use undiluted coolant, obviously, to achieve the 1:1 ratio. I should buy a coolant checker but around here in the Pacific NW we don't get so cold that I worry about getting it to exactly 1:1. I'm usually a little more water than coolant. There is a spec for the Universal engines that lists the cooling system capacity. Let me know if you need it.

Air bubbles are going to get in there with this method and I run the engine for a while to leak check, and refill as needed. I also check the coolant for the next couple hours of running time and have coolant available to top it up. I haven't tried any other method to burp the air out. I took pictures of an M-40 I was thinking about buying and on that engine there is a Schrader valve on top of the thermostat housing. That is pretty close to the high point of the engine cooling loop and is probably a help. But I suspect that bubbles collect in other places.

For draining purposes, there is a Schrader valve on the side of the engine block near the front on most of these Universals. Mine is in a bad spot under the forward part of the intake manifold and I never use it. I never found it until I had the head off the engine last summer. You could disconnect a hose at a low point but you'll usually have a lower point internally. As I mentioned above, I use undiluted coolant to achieve the 1:1 mix since water is left in the engine.

It's always an adventure.
 
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Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
My M25xp has a drain plug in the coolant reservoir and one on the bottom of the HX. There is probably one in the water jacket as well (at least there was in my old A4).
Engine schematics can be found here. Takes a bit of sifting thru.
http://shop.toadmarinesupply.com/ma...contentsection=universal&contentname=catalogs

That "plug" on the bottom of your heat exchanger should be the end of the plug that holds a short threaded-in zinc. I have that on our M25XP.
Darned... difficult to reach.
 
Coolant flush

Hi JSM,

This is an older post, but we have recently purchased an 30+ with a universal M18. When we opened the thermostat casing we had a similar gelatinous material. When you did the coolant flush, did you use a cleanser for the flush? Any lasting issues?

Thanks in advance.
 
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