470 cracked heat exchanger

[jsager]

"Hello
I have a 470 Merc in a

"Hello
I have a 470 Merc in a 19.5 Glasply that belongs to a friend. It overheated due to leaking front heater tubes so he had a new head gasket,head planed etc at a marine shop.They DCed the heater. He then bought a new boat. The shop tested it a year ago and it has sat since. I drained the old gas and put the ears on yesterday, fired it up and was amazed how nice it ran until I noticed water coming from cracks in the heat exchanger. He neglected to drain the seawater side and we had a cold winter.
I had noticed what looked like engine oil coming out of the water intakes on the leg previously but this morning there was coolant dribbling out.
My question is if I take the exchanger to a rad shop and have it repaired what else might be damaged due to the freezing and what seal may be leaking down into the leg.
It is a well maintained freshwater boat and I would like to keep it.
I did drain out some gaer oil from the leg and it looks good.
Thanks in advance"

 

[guest]

"If it was just an end cap tha

"If it was just an end cap that was pushed out that's one thing, but split open is another story. I'd buy a new exchanger. Done. As for all this coolant and oil in the exhaust i think you need to fix the cooling system and run the engine before you will know for sure if there is any other damage. If there isn't any water in the oil i doubt the oil circuit is damaged.
The exchanger may have broken on the coolant side as well and now the coolant is mixing with the seawater and exiting with the exhaust.
But seeing how (if i understand this) the head was shaved / reworked do not discount a problem there.

Good luck."