Coolant not light green?

[kcncolby]

I have twin ford Lehman120's. Flushed out both coolant systems and one is bright green, like it is in the right out of the bottle. The other one is a real dark green color? Any suggestions why and what should I do?

Thanks,

Gary

 

[O C Diver]

I have twin ford Lehman120's. Flushed out both coolant systems and one is bright green, like it is in the right out of the bottle. The other one is a real dark green color? Any suggestions why and what should I do?

Thanks,

Gary

Need more information. Did you change both engines coolant last time at the same time with the same mixture? Were any additives put in the engine with the dark colored coolant from last change till now?

Ted

 

[kcncolby]

I changed them both at the same time. The one was a darker color green to begin with, that's why I changed it, but after using a flush out it's still the same?

 

[RT Firefly]

Greetings,
Mr. k. If this is your first flush could be the PO mixed and (un)matched coolants at some point or as Mr. OC suggested an put in an additive of some sort (hopefully NOT leak stop). Since you have the systems emptied and flushed, simply add proper concentration of what-ever Lehman suggests to proper levels. If this is a discoloration of something you've done, I haven't got a clue.

 

[kcncolby]

Thanks for your inputs. I noticed the darker color on the port engine and decided to change it when I did all the other fluids on the both engines and transmissions. I used a prestone flush out system for each engine. Added water and ran it for thirty minutes then drained them and added a 50/50 mix of new coolant. Ran the port engine for about three hours and it's still a darker green? The other engine is lime green and looks great? Thanks! Gary

 

[O C Diver]

When you ran the engine that turned darker green, did the level in the plastic over flow bottle for the coolant system, rise? Is the water where your boat is a dirty brown color? Wondering if you might have a leak in the heat exchanger that is pushing out coolant as the engine warms up and sucking in raw water as it cools down.

Ted

 

[psneeld]

Was the darker colored coolant on an engine that also contained the hot water heater loop?

If so, mine was the same way till I flushed the loop to the hot water heater very well several time which I think the PO was not doing.

The first time I did mine, everything looked well until I ran the engine, within a few minutes my brand new coolant looked diluted and dirty.

 

[kcncolby]

Actually it is not the engine that's hooked up to the water heater. Ted, I never even thought of that. How would I know if the exchanger is leaking into it? Thanks Gary

 

[O C Diver]

Start by putting a piece of tape on the coolant over flow tank to mark the coolant level when the engine is cold. Then start the engine up and bring it up to operating temperature. If the level doesn't rise, it means the pressure cap isn't venting excess pressure (coolant). If the system is full of coolant, the excess has to go somewhere when the engine warms up. If the level doesn't rise when the engine warms up, and the coolant level is full inside the engine when it cools back down, the heat exchanger is where I would start. When was the last time the zincs were changed on the heat exchangers, and what was left of the old ones?

Ted

 

[kcncolby]

Ted, I actually change the zincs quite often. Just changed them two weeks ago. Not much left when I did it though, maybe 3/4 of an inch left on them? I also bought two new radiator caps from American diesel about six months ago. I'll try your method and see what happens. Thanks again! Gary

 

[kcncolby]

Ted, the water did rise on the darker green one. But, it didn't rise on the good clean one?

 

[FlyWright]

Is the water where your boat is a dirty brown color? Wondering if you might have a leak in the heat exchanger that is pushing out coolant as the engine warms up and sucking in raw water as it cools down.

Ted

Is that what would cause a brown color to the coolant?

 

[chc]

Might want to try a pressure test on the cooling system; would show any leaks pretty quickly.

 

[O C Diver]

Ted, the water did rise on the darker green one. But, it didn't rise on the good clean one?

Should have told you to pull the radiator cap to check to make sure the expansion tanks were full. The one that didn't rise, may have had some air in the top of the expansion tank. If so, when it got warm, only air may have been pushed out, which wouldn't change the fluid level in the over flow tank. At some point, all the air should have been worked out of the system. You should expect to see the coolant level in the over flow tank to rise and then fall every time you run the engine.

My next step would be to get some antifreeze test strips. They change color to indicate the protection level of your coolant. If the strips show a lower protection level than the other engine, you coolant may be getting diluted with raw water through the heat exchanger.

Don't want to call into question your engine flushing, but you may have a pocket of sediment that resists flushing.

Pressure testing the fresh water side of your cooling system with a radiator tester is another good idea.

Ted

 

[O C Diver]

Is that what would cause a brown color to the coolant?

It's one possibility. If your coolant has broken down, or there is only water, the block may be rusting which would change the color. Salt water intrusion through the heat exchanger will rust the block and the color of the coolant very quickly.

Ted