454 heat exchange coolant 1988 silverton

[tcarriere]

I checked the heat exchange coolant fill tank to see if I need to top these off with coolant.
The yacht is a 1988 yacht with twin 454 engines with the heat exchange on top of the engines.
When taking off the coolant caps when engines cold, it was about 4" below the cap. The color was dark red like the color of fresh automatic transmission fluid. What kind of coolant is these systems now? When should i add coolant and what should I add? I have never seen this color of coolant in any cars I have worked on in 30 years. I have seen the year 2000 GM pink coolant and the 2000 GM pink coolant is much lighter pink than what i see in these 454 boat heat ex changers.

 

[billm]

Could it be just rusty water?

 

[cmariner32]

My '89 454 Crusaders use regular green antifreeze. I have overflow tanks that I added as a safety net. I always check my HE and make sure the coolant is maybe an inch or so below the cap. I cannot think of any instance where the coolant would be red. Rusty water is usually more brownish. If this is a new-to-you boat, you might want to consider flushing out the old and put in new antifreeze if you don't know how old the existing coolant is. Antifreeze does go sour after so many years and can turn acidic.

 

[GeeBee]

Old Dexcool turns dark red.

 

[Good Grief]

Mercruiser's FWC coolant is red - My dealer put that system on my 5.7 Volvo Penta's pre-delivery (as Volvo didn't offer FWC on stern drives back then) . . . been using red coolant ever since.

 

[tcarriere]

Thanks for your help. It appears like the fluid smells like coolant with good viscosity. The darker red may also be because the book says 60% coolant and 40% water. Maybe the prior owner put 75% coolant and 25% water. The red dexcool is hard to find so I guess I will have to use the autozone coolant that says it can be mixed with any color and i will keep the level 1" under the fill cap.