Volvo penta 5.7 gsi thermostat leaks

[murphywp]

Hi I Have a 1999 Volvo Penta 5.7 gsi motor in a Four Winns 258 Vista it has a San Juan closed cooling system. The thermostat housing is leaking from where the housing mates up to the Manifold. I have taken the boat back to the Mechanic three times and he says he sanded down the housing so it would seal better to the manifold. Well after a month its now leaking again, I asked the mech if he could not just change out the housing he says that the manifold is not the stock manifold and so he can't find the right themostat housing. So only way to fix is to change out the manifold which is not cheap. I have trusted him for many years but he is not the one turning wrenches as much cause his shop has expanded and he has mechanics working for him. Anyway does anybody have a part number for that year of thermostat housing so maybe I could look at it and see if looks like the one that on it right now? Any help would be appreciated.

 

[Lou C]

I would not change the manifold, that really should not be necessary. If the housing leaks try sanding down the sealing surface of both the manifold and the themo housing again and use a new gasket coated on both sides with OMC gasket sealer or Permatex Aviation sealer. If it still leaks contact San Juan and see if you can get another housing from them. It will be cheaper and much less work than changing an intake manifold.

 

[Scott Danforth]

call san juan. the manifold is most likely the factory manifold. the thermostat housing is from San Juan (part of their kits)