Volvo 3.0 GS - Cracked manifold problems

While driving on the lake, my boats exaust grew louder and louder, the engine compartment got really hot and there was a significant loss in power. Suspecting the manifold, i pulled it off only to find that the previous owner had welded a cracked manifold. The manifold wasnt any leaking water while i was slowly driving it back to shore, but i still suspect that a cracked manifold is my problem. Are there things i need to check my engine for before slapping a new manifold on and trying to start it up. (I've already checked for water in the oil and found none). I'm just worried that the cracked manifold may have caused other significant problems expecially since it got so hot and lost power. My engine is a volvo penta 3.0 gs, which i have found to be known for bad manifolds. Thanks for the Help!

Re: Volvo 3.0 GS - Cracked manifold problems

I'm just worried that the cracked manifold may have caused other significant problems expecially since it got so hot and lost power.

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Ayuh,... A Compression Check is probably in order.....

Re: Volvo 3.0 GS - Cracked manifold problems

Was the raw water pump working at all? No cooling water causes overheats.

Re: Volvo 3.0 GS - Cracked manifold problems

I had the boat out the day before and the day before that with no problems with overheating. I'm guessing that the raw water pump was working properly. I think it's a cheap and easy replacement, probably not a bad idea to go ahead and change it while the boat is down. Thanks for the advice guys.

Re: Volvo 3.0 GS - Cracked manifold problems

I would pull the spark plugs and turn the engine over, prior to starting, to make sure the manifold did not leak in to a cylinder. Other than that, straight replace.

It would stand to reason that if your manifold was cracked it would leak cooling water in to the bilge.

Re: Volvo 3.0 GS - Cracked manifold problems

When I pull the plugs and turn it over I should be looking for water coming out of the sparkplug holes right? I should have mentioned earlier that the manifold got so hot in the area it was patched before that the paint peeled. So although I didn't see it leaking water, I still suspect it is the problem.