Logo

2007 496 Ho mag coolant Tank keeps overflowing

luis varela

New member
my engine has not yet over heated or any alarms but all of a sudden my coolant tank is empty and when i fill it up it starts to fill up and overflow
 
Ayuh,..... Sounds like ya got a leak,...... drain it, pressure test it,..... follow the sound of the escapin' air,......
 
What do you mean leak and listen to air ?

could The overflow be caused by a bad heat exchanger ? A bad thermostats? Or and issue with my hot water heater?
 
Things that will over fill your expansion tank:

Blown head gasket
Leaking Heat exchanger between the sea water and coolant with a blockage in the raw water side sending the pressure in the exchanger over the limitations of the pressure cap.

The water heater can do this if the coil inside is compromised and the domestic water system is pressurizing the antifreeze side, but not likely.


I would say your exchanger is leaking and your raw water side has high pressure.
 
Hello again everyone.

Chris thank you for your detailed response. Today I bought a new heat exchanger. Which was expensive. I took the old one out along with the crossover. I noticed salt residue in the crossover. I clean it out replace all gaskets and swap out the heat exchanger. I ran the engine on low and high idle. And the water in the reservoir stayed pretty Mich the same. Unlike before it would fill the tank up in 30min. I have not sea trailed it yet. But I hope froml what I sea on high idle and low idle, I believe we are good and the problem has been fixed. I’m still spectacle on the hot waterl heater. It’s old and still all original.

Any my more thoughts on my case would be appreciated.

Thank you !!

luis V
 
Most exchangers just lose coolant into the sea water, If you were pushing sea water into the Coolant side of the exchanger, you need to check the pressure in the raw water side!

If you have a smartcraft gauge you can see what the pressure is. If not, find someone who has a scan tool.
 
Back
Top