Warm water in bilge after a day on the lake

[Cos_man99]

Sorry if there is already a thread on this. I did a quick search and found nothing. If there is a thread please feel free to direct me there.

1996 Sundancer 290 (Trailered boat. No slip)
7.4 Mercruiser Bravo 3
No generator or A/C

After a day on the water, after getting in on the trailer, when I pull the plug there are several gallons of warm water that run out. It seems obvious to me that it is coming from the engine somewhere. I ran it today at various RPM's and shot all kinds of GoPro footage all around the engine (someone else driving while planed out cruising down the lake, while putting slowly, etc.) and can find nothing. None of the video I shot shows a leak anywhere. Is there a chance that it is somehow coming from the outdrive (through a bellows)? Would it be warm? I'm guessing it is as warm as what one would use to draw a kid's bath. It is prob around 100 degrees I'd guess. Makes me think it is not a thru-hull leak. It must be engine related right? Any ideas of where to look? Thanks!

 

[Golfman25]

So as you where shooting the footage, was you bilge filling up? I have had the issue from a loose drain plug on the engine/riser. Also a cracked riser.

 

[JimG]

Hot water tank (heated by exchange) leaking?

 

[Espos4]

Don’t rule out lake water just yet.

The water from the 20 gallon water tank on my boat gets very warm after a day on the water.

The heat from the motor could warm any water entering from an external leak.

 

[Thornton69]

Several gallons? You may want to check your bilge pumps..
Before we replaced our steering pin, we might have got one and it was always warm. Stays dry now.

 

[Cos_man99]

Thanks for the replies guys. I thought I would be notified via email if anyone commented on my thread. I guess not. I thought I'd check back to see and here you all are.

I do think I have an issue with the automatic bilge pump. I am going to have to stand on my head to figure out what is going on with that one. I can hit the switch on the dash to turn the other pump on to pump it out. It is odd to me though that the pump is mounted in a place that at least a gallon or two remain in the bilge after pump can no longer pump any more water (pump is mounted on a high spot on the floor of the bilge area).

I cannot tell if there is new/more water coming in by looking at my footage. I had been in a slip for a few days (with many trips away from the dock so there was a decent amount of water in there already before I started my investigation.

I worried about the steering pin as that seems to be a problem on this era Bravo 3's but when I look around the upper part of the hole through the transom and the whole transom area I can't see any evidence of water coming in there.

I checked the hot water heater and the hoses going to and from and don't see any evidence of leaking there.

 

[Little Ducky]

Any water leaking down the front side of the motor by the belts?

I had to replace a water pump last year on one of my 5.0's and it was hard to find the leak at first until I saw the water being flung by the belt.

 

[Cos_man99]

Any water leaking down the front side of the motor by the belts?

I had to replace a water pump last year on one of my 5.0's and it was hard to find the leak at first until I saw the water being flung by the belt.

None that I can see.

 

[Lazy Daze]

Several gallons in the bilge is typically not nearly enough to get the bilge pump to turn on. It's mounted the way it is out of necessity. It needs to mounted to a block of wood rather than directly to the hull bottom. Plus, the angle of the hull prevents the pump from being mounted level. Just lift the float switch to see if it works. But, you can never get all of the water out of a bilge using just the pumps.

Empty your fresh water system completely. Get rid of that variable.

 

[Cos_man99]

Several gallons in the bilge is typically not nearly enough to get the bilge pump to turn on. It's mounted the way it is out of necessity. It needs to mounted to a block of wood rather than directly to the hull bottom. Plus, the angle of the hull prevents the pump from being mounted level. Just lift the float switch to see if it works. But, you can never get all of the water out of a bilge using just the pumps.

Empty your fresh water system completely. Get rid of that variable.

Thanks. I will try that.

 

[Ozshadow]

Run it on the muffs for a good while. If no water in bilge, it probably means a transom leak.