Coolant testing

Joined
Sep 1, 2021
Messages
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Is there a service to test antifreeze? I'm thinking something like there is for oil where you send in a sample and they tell you what's in it (contaminants).

I have a liquid cooled generator. The coolant has some form of goop (highly technical term) in it. I've flushed the coolant and it's still there. In fact, it didn't fully leave because the flush chemical didn't really break whatever this is down.

Some background:
There's a technician that has worked on my generator for many years (before I even owned the house) and he said he flushed it out before too. He was stumped at what it was too. Then he called me back and said his conclusion is that there is a head gasket issue and that oil is getting into the antifreeze. While this seem logical, I'm not convinced. There is absolutely no clouding of the oil. I would think if the head gasket was the issue, it would show up with antifreeze in the oil.

In the generator manual, it states that a low silicate antifreeze needs to be used and if you use a chromate based rust inhibitor, you can get green slime. I'm wondering if this happened or if at some point someone used the wrong antifreeze and the mixture of two antifreeze types is causing the problem. I've gotten some of the goop on my hand and it does not seem to be affected by a degreaser - leading me further to be skeptical about it being a gasket leak and oil in the antifreeze. However, I don't know what oil would do when mixed with antifreeze.

The good news is that the generator still operates and does not over heat. I've changed the antifreeze out twice now. This year I just dumped and refilled. I'd like to get to the bottom of this and get a clean coolant system. Is there any testing lab that could identify what this stuff is so I can correct the situation?

Thanks.
 
I've had good luck using powdered dish washing detergent (Cascade) when flushing an oily cooling system. Just make sure to flush thoroughly afterwards.
 
Can you give us a little more info? Might be helpful to know the manufacturer, engine, etc... NG, LP, or gasoline? Could the wrong antifreeze have been used?
 
It’s a small Mitsubishi engine. It is natural gas powered. It’s basically a small car engine. 4cyl. I think about 1.6 liter.

Yes, it’s entirely possible that the wrong antifreeze was put in it. However, I don’t know how to verify that or what to do if that is indeed what happened.

I was also looking for input on the thought that it could be a head gasket issue and whether my logic is correct for ruling that out (the oil does not appear contaminated).
 
Visible water on the oil is kind of a wives tale unless you have been nursing along a major problem for a long time. A small leak won't put enough coolant into the oil to see. It will show up in a test.

Is it grey mud? If so that's oil. Black slimy chunks are hydrocarbons.
 
Visible water on the oil is kind of a wives tale unless you have been nursing along a major problem for a long time. A small leak won't put enough coolant into the oil to see. It will show up in a test.

Is it grey mud? If so that's oil. Black slimy chunks are hydrocarbons.
I don’t think I’d call it grey or mud. It’s brown and slimy. However, I change the oil frequently and the engine doesn’t get all black (oil stays pretty clean) due to the natural gas, so maybe that’s why it’s not black. The feel of it is something else. It doesn’t clean off well with soap or a degreaser which makes me wonder if it’s oil. But, once combined with antifreeze, maybe it has different properties than oil alone.

If the coolant will show up in a test, them maybe that’s the answer. After I run it for the next outage, something more than just a couple hours, have the oil tested for coolant. I was thinking of testing the coolant for oil. Maybe do both. Unfortunately, our electric grid around here will most likely give me an opportunity to run it for awhile some time in the near future.
 
Fleetguard partners with Polaris Laboratories under a program called Monitor; you can check out the coolant sampling kits here: https://www.cumminsfiltration.com/sites/default/files/LT36251.pdf

As for a cleaning agent, we definitely do not recommend using soaps or detergents in engines...that can cause some issues with foaming if you don't get it all out, which it's tough to get it completely out. I would recommend checking out one of our two cleaning products called Fleetguard Restore; it's an alkaline-based chelating cleaner designed to remove soft contaminants out of your engine's cooling system: https://www.cumminsfiltration.com/sites/default/files/lt36625.pdf
 
The absence of antifreeze in the oil does not mean the head gasket isnt bad. You could use a Lisle tester and check for hydrocarbons in the coolant tank. My bet is the mechanic was correct.
 
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