can't find coolant leak!?

rednek9

Recruit
Joined
May 19, 2015
Messages
2
I have a mercruser 350 Chev,not sure on year.but I have been chasing a ghost leak. I started loosing coolant in my closed cooling. I replaced riser gaskets and i took it out a few weeks after and I ran about two hours 3200 rpm and came to an idle and it over heated. Filled the heat exchanger back up and at 3200 rpm it runs dry in about 5 min. At idle it seems to stay full? so today I took the heat exchanger off and pressure tested it and it held 25 psi all day. Even heated it up to about 160 ?. No leaks. Oil stays clean as the day it was changed and engine runs great with no lack of power so I don't think its h/g problem. Could my new riser gaskets be leaking or something?!?! Thanks in advance! - nick
 
Last edited:

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
51,904
did you use OEM gaskets or the green leakers from Sierra?
 
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