Mercruiser 4.3 back in the water

[Manta Ray]

Just back from 10 months deployed. Only drained the manifolds and lowered the sterndrive. Just returned, cranked her last weekend, the plastic hose fittings (drain valves) underneath each manifold were leaking and cracked. Bought replacement fittings, Mercruiser replaced with metal ones. If I froze last winter what else do I need to look at? Could my only problem be the hose fittings? Should I have the exhaust elbows and manifolds reconditioned?<br /><br />Thanks

 

[PlanB]

Re: Mercruiser 4.3 back in the water

If you froze anything it will either be leaking water or getting water in the oil. If the manifolds froze and cracked internal you will get water in a cylinder after shutdown and will lock of the engine until the water is cleared. Check the oil to see if it is milky. I had 4.3 mercs and I always drained both block plugs and manifold plugs, drained circulation pump then filled it up with anifreeze mix thru the thermostat housing.

 

[andrewgroup]

Re: Mercruiser 4.3 back in the water

Manta Ray,<br />Thank you for your service to our country. I have friends and family that have paid the ultimate price for freedom.<br /><br />Regarding your boat, I would do some compression testings both wet and dry with all plugs removed and the distributor cap removed. With more information about the engine, I'm sure the group can find the specifics on what the compression numbers should be. You might also look on the local TV's weather stations WEB sites and get a review of the high/low temperatures for your city to get an idea if you had any deep freezes. It's arguable about how cold and for how long it takes to crack and engine block.