4.3L Volvo Penta - Water Intrusion

[MightyMo77]

I have a 1996 Volvo-Penta 4.3L motor that I've owned now for 4 seasons. Sorry for the length of this post, but I think the background is important. Ran the boat once this season. On the second trip, boat overheated. The impeller in the lower water pump was gone. I replaced the impeller and started it up again on the muffs. It was a slow start but ran fine after it started. A few days later, I tried to start it a again on the muffs, but it hydrolocked. Only problem was, I didn't know that was the problem initially, because when it hydrolocked, the housing on the starter broke, so I thought I was having starter issues. Replaced the starter, ran the boat on the muffs again last Saturday. It was slow to start but ran fine after it started. Last Wednesday, I tried to start it again - hydrolock. Pulled the plugs, expelled the water, etc. Water came out of cylinders 4 (starboard) and 3 and 5 (port). Today, I pulled the exhaust manifolds and risers. Keeping in mind that I'm a novice mechanic, they appeared to be fine. Didn't see any apparent issues with the gaskets (although leaky manifold gasket on the port side seemed possible). I also pulled the head off the port side (haven't gotten to the head on the starboard side) - water on top of cylinders 1 and 5. The head gasket seal appeared to be fine.

So, I'm not sure what the best course of action is at this point. Should I replace all the gaskets, put it all back together, and see what happens? Is there anything else I should do? Is there a good way to test the manifolds for cracks? I don't see any, but I realize that doesn't mean there aren't any.

Thanks in advance for any suggestions you can provide.

 

[havasuboatman]

Re: 4.3L Volvo Penta - Water Intrusion

I have a 1996 Volvo-Penta 4.3L motor that I've owned now for 4 seasons. Sorry for the length of this post, but I think the background is important. Ran the boat once this season. On the second trip, boat overheated. The impeller in the lower water pump was gone. I replaced the impeller and started it up again on the muffs. It was a slow start but ran fine after it started. A few days later, I tried to start it a again on the muffs, but it hydrolocked. Only problem was, I didn't know that was the problem initially, because when it hydrolocked, the housing on the starter broke, so I thought I was having starter issues. Replaced the starter, ran the boat on the muffs again last Saturday. It was slow to start but ran fine after it started. Last Wednesday, I tried to start it again - hydrolock. Pulled the plugs, expelled the water, etc. Water came out of cylinders 4 (starboard) and 3 and 5 (port). Today, I pulled the exhaust manifolds and risers. Keeping in mind that I'm a novice mechanic, they appeared to be fine. Didn't see any apparent issues with the gaskets (although leaky manifold gasket on the port side seemed possible). I also pulled the head off the port side (haven't gotten to the head on the starboard side) - water on top of cylinders 1 and 5. The head gasket seal appeared to be fine.

So, I'm not sure what the best course of action is at this point. Should I replace all the gaskets, put it all back together, and see what happens? Is there anything else I should do? Is there a good way to test the manifolds for cracks? I don't see any, but I realize that doesn't mean there aren't any.

Thanks in advance for any suggestions you can provide.

You overheated your engine, now you have water in at least 4 different cylinders.
Either the block, or the heads (most likely) have cracks in them.
Sorry, but this is gonna get expensive

 

[Don S]

Re: 4.3L Volvo Penta - Water Intrusion

You talked about manifold gaskets, hope you weren't looking at the gaskets between the manifold and the head. The ones you should be looking at are the ones between the manifold and risers. THAT is where water gets into the cylinders from. That or cracked risers or manifolds.