Coolant fluid leak

[Frank Medina]

Hello,
Anyone know what could be the problem?
When I’m running, the coolant fluid stays the same.
When I shot off the engine, the fluid still the same level.
About an hour later the fluid in the reservoir is down about an inch.
After several hours the reservoir goes even lower.
I took the cap off and the fluid is all the way to the top.
The engine is a QSC500 560 hrs.2007
Any idea? I would appreciate any help.
Thank you.
Frank

 

[sbw1]

Are you adding coolant and this pattern repeats? Did you recently flush the system and refill it? Both engines doing this?

 

[Frank Medina]

I did change the fluid and replenished only two times for a total of a gallon.
The other engine doesn’t have any loss of fluid.

 

[sbw1]

Having to add coolant after a flush and refill is common in my experience. The system has a little air in it after you drain the coolant down. When you replenish it the air has to work its way out. As it does this the overflow tank level drops until the engine block is free of air and full of coolant. Just keep adding fluid to the overflow tank, keeping it between the the min and max level. It will stabilize as you run the engine, and should stay at that level until the next fluid change provided there is no leak. I have not added coolant to my engines in three years, the last time the ph reached the level indicating it needed to be changed.

 

[Frank Medina]

Are you adding coolant and this pattern repeats? Did you recently flush the system and refill it? Both engines doing this?

I did flushed the engines and put new fluid.
The other engine doesn’t have a leak.
I did replenished the one eng two times.
For a total of about a gallon.

Having to add coolant after a flush and refill is common in my experience. The system has a little air in it after you drain the coolant down. When you replenish it the air has to work its way out. As it does this the overflow tank level drops until the engine block is free of air and full of coolant. Just keep adding fluid to the overflow tank, keeping it between the the min and max level. It will stabilize as you run the engine, and should stay at that level until the next fluid change provided there is no leak. I have not added coolant to my engines in three years, the last time the ph level reached the level indicating it needed to be changed.

You are a life saver!
Thank you and I will follow your suggestion.
Thanks again.

 

[sbw1]

Keep an eye on it. Should be fine after you run the boat and top off coolant maybe 2-3 times. Make sure you use compatible anti freeze if you run out and need to buy another gallon. Orange and green are not compatible and mixing them causes major damage.

 

[Frank Medina]

Keep an eye on it. Should be fine after you run the boat and top off coolant maybe 2-3 times. Make sure you use compatible anti freeze if you run out and need to buy another gallon. Orange and green are not compatible and mixing them cause major damage.

Will do.
I have two gallons left of the same.
Thanks again and I will keep you posted.

 

[sbw1]

Not sure what color you used. Cummins standard life Coolant is green I believe. They also used extended life which maybe is blue. You should consult your owner manual to be sure. Also read about aftercooler service intervals. Maybe a Cummins owner will comment?

 

[Frank Medina]

Not sure what color you used. Cummins standard life Coolant is green I believe. They also used extended life which maybe is blue. You should consult your owner manual to be sure. Maybe a Cummins owner will comment?

Is the blue for cummins. That’s the one I’m using.
Thanks again.
PS. That loss of fluid, the first time went down to about an inch from the bottom. The second time only about an inch front where’s supposed to be. I think you are right on the air pockets.

 

[my3sons]

Cummins engines are not particular about the coolant. As said above, certain coolants should not be mixed. C series engines have cylinder liners and require additives to prevent liner erosion from cavitation. Those special coolant additives, called SCA's, will be shown on the labeling of the coolant you choose.
To keep things simple, you can use Fleetguard ES Compleat coolant. (it is blue)
If you ever have an issue and need to add coolant beyond the gallon or so that you carry as a spare, Cummins states that ES Compleat is compatible with anything that you can buy for fleet maintenance at major auto stores or truck stops.

 

[Frank Medina]

Cummins engines are not particular about the coolant. As said above, certain coolants should not be mixed. C series engines have cylinder liners and require additives to prevent liner erosion from cavitation. Those special coolant additives, called SCA's, will be shown on the labeling of the coolant you choose.
To keep things simple, you can use Fleetguard ES Compleat coolant. (it is blue)
If you ever have an issue and need to add coolant beyond the gallon or so that you carry as a spare, Cummins states that ES Compleat is compatible with anything that you can buy for fleet maintenance at major auto stores or truck stops.

Thank you Sir for the information.
Yes I use the blue one, only what Cummins recommends.

 

[Frank Medina]

Hello Gents,
A follow up on the loss of fluid, I ran the boat today and didn’t lose any fluid at all. Case closed!
Again, thank you for your help.
Best regards
Frank

 

[sbw1]

Hello Gents,
A follow up on the loss of fluid, I ran the boat today and didn’t lose any fluid at all. Case closed!
Again, thank you for your help.
Best regards
Frank

Glad it worked out for you. Make sure you do the PM on the intercoolers, and other related systems.

 

[Frank Medina]

Will do.
Thank you.