VP3.0L: Exhaust Overheat alarm is screaming

[schak]

I have a Volvo Penta 3.0L (GSP-B) Sterndrive engine.

Rookie boat owner, only had the boat for 2 years so be gentle.

After some troubleshooting of the alarm using muffs I determine that the exhaust overheat sensor is asserting. The asserstions happens after the boat has warmed up and asserts at idle as well. I can feel the exhast coming out of the propeller, but don't see any water. Is there supposed to be water comming out of the properller?

What I see happening in the engine compartment is water is coming out of the "core plug" hole. I don't ever recall seein that before. Attached is a picture that may show better what I mean.

What do you think is wrong with this boat?
Thanks in advance.

 

[danond]

Re: VP3.0L: Exhaust Overheat alarm is screaming

Most likely, someone didn't winterize it properly, and there's a chance (a very good one) that your block is now cracked from water freeze damage.

Pull the dipstick, check the oil. Is the level too high? Is it chocolate milkshake colored? If so, you need a new engine.

There's a chance that the plug just fell out. That can happen (it's rare). Get the plug back in the engine and test again.

 

[schak]

Re: VP3.0L: Exhaust Overheat alarm is screaming

The oil looks good and clear, it does not look milky. Where the water comes out, it's a perfect circular hole about the size of my thumb. So I don't think it is a crack, seems like a purposely made hole. Is there normally a plug that should go there?

The alarm started last fall on our way back to the boat ramp. The boat have been winterized and I haven't use the boat since then.

 

[Jeepster04]

Re: VP3.0L: Exhaust Overheat alarm is screaming

If the water is coming out of the bottom of your exhaust then they may of forgotten to put the plug back in.. Makes sense if its the size of your thumb.

 

[captmello]

Re: VP3.0L: Exhaust Overheat alarm is screaming

That is a core plug and shouldn't be out. You need to replace the plug and hope that is your only problem.

Those holes are created during the casting of the manifold and are commonly pushed out by freezing water.

as mentioned before, replace plug and test it out.

 

[blazer7]

Re: VP3.0L: Exhaust Overheat alarm is screaming

I've also had my exhaust sensors go bad on me so that's something to keep in mind..... but first replace them plugs.

 

[schak]

Re: VP3.0L: Exhaust Overheat alarm is screaming

I believe I have fixed my problem; thanks for all the suggestions. Thought I'd post my resolution so other can get learn from it as well.

I found the core plug at the bottom of the engine compartment. I cleaned it up and plug it back into the core plug hole. I'm suprised that it popped out in the first place, because it was pretty tight fit on its way in.

I ran on muffs intially on idle for about 5 min, then on "wake" for about 5min more and was able to see water flowing out of the propeller. Then I rev the engine up a little bit higher for a few of minutes, then put it back to wake speed. Everything appears normal no alarm, before after the initial wake test the alarm would sound and stays on. I checked the engine compartment throughout the testing and did not see any water leakage.

I may be one of the lucky ones, don't think there are any cracks in the engine. But will feel alot better after testing it out on the water with WOT thought.

Thanks to all

 

[Bt Doctur]

Re: VP3.0L: Exhaust Overheat alarm is screaming

Sorry to inform you that they don`t "POP OUT" by themselves,there forced out by freezing water.You just may be one of the very,very very few that did not suffer a cracked block.
.Review your winterizing procedures

 

[son_in_law]

Re: VP3.0L: Exhaust Overheat alarm is screaming

My mother in law has a penta 5.7 and we are getting overheating warnings. We put on a new impeller, thermostat and seawater pump. We were still getting overheating problems when we took it out last weekend. I think there may be something clogging the exaust. Any theories?

 

[Zackman]

Re: VP3.0L: Exhaust Overheat alarm is screaming

Son In Law. You should start your own post... you'll get better answers and won't confuse others including the original poster of this thread.​