Cracked Exhaust Manifold.

hbrownlee

Recruit
Joined
Aug 14, 2007
Messages
4
I need your opinion. Last spring I bought a 1977 Carver with twin inboard mercruiser engines. The previous owner and several people at the marina said the boat was in excellent mechanical condition with no problems at all last year. The boat was winterized and stored out of the water last winter. When we test drove the boat, my wife noticed white "smoke " coming from the starboard exhaust. The owner said it probably was the old gas, and we thought no more about it.
I bought the boat, and the first time we went out the starboard engine stalled. I checked the oil and found it was milky and way over filled. The problem turned out to be a cracked exhaust manifold. $1,500 later I'm trying to understand if the boat ran well last year, what would cause the exhaust manifold to crack? Can it just fail that quickly, or could poor winterizing be the problem?
What is your opinion?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Cracked Exhaust Manifold.

Have you run the boat since you installed the new manifolds? Water leaking from a cracked manifold will leak water when it's NOT running. So the water in the manifold gets on the pistons and you have a hydrolock. If the oil is filling WAY over full and milky, my guess is you have a cracked block. probably from faulty winterization.
 

hbrownlee

Recruit
Joined
Aug 14, 2007
Messages
4
Re: Cracked Exhaust Manifold.

Boat runs fine now, Don. I'm trying to decide if I just had some bad luck, or I need to find a new mechanic to winterize this season.
Thanks for the input
 
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