Baffled with engine issue

[Ron Hill]

Chuck : Check the raw water seacock with the strainer.  Turn the seacock off (90degrees to the flow) and start to unscrew the strainer.  You should only get the water in the strainer.

If the water keeps on coming you have a jammed OPEN seacock and turning the handle does nothing!!  That could explain what's happening.

A thought

[Kevin Henderson]

Definetely sounds like a mystery.  However, It is only logical that the water must be coming through one of the thru huills you have identified as feeding the cooling water. 
In order to deconflict any possibility of confusion with either of the tryu hull valves, I would close one with the engine running.  As soon as you see that the exhaust no longer has water... thats your valve. 
The water has to be coming from somewhere. 

[chuck53]

Chuck : Check the raw water seacock with the strainer.  Turn the seacock off (90degrees to the flow) and start to unscrew the strainer.  You should only get the water in the strainer.

If the water keeps on coming you have a jammed OPEN seacock and turning the handle does nothing!!  That could explain what's happening.

A thought

Ron, with the seacock closed, I can open the strainer and no water comes out.  As soon as I start to open the seacock. with the strainer open, water starts to pour out.  Again, everything seems to be working as it should be and all hoses, repeat ALL hoses and seacocks are connected properly.  I've had this boat for 3 years and no hoses have been touched.
I thought about the seacock being jammed open (which it's not), but if it was jammed open, how can there be AF still in the strainer after running the engine for 45 minutes.

[chuck53]

The only explanation I can think of that could be remotely possible, since there is no other water source coming to the engine that I can see, is a partially defective seacock.  The seacock does work since when closed I can open the strainer and no water comes out.  Maybe, just maybe, with the engine running, the water pump has enough suction that it pulls water through the closed (partially defective) seacock.  I know that sounds strange, but it is the only plausible explanation I can think of.  I'm sure the water flow is somewhat reduced, but with the cool air and water temperatures this weekend, enough water was sucked past the closed seacock to keep the engine within normal operating temperature range.
The only downside to that explanation is the AF still in the strainer.  The next time I'm on the boat, I will test my theory.

[Indian Falls]

Wow.. this is a good one.  Can you tell us after 30 min run time you looked over the back of the stern and saw water coming out with the exhaust?   Your thru hull is not the problem.  The impellor can't create enough vacuum to suck water past a closed ball valve.  Your impellor may be ok in that as long as fluid was present for lubrication, it doesn't care that water is being pumped.  Maybe your thermostat is stuck open, you might get quite a bit of run time before overheat if this were the case. 

[Ron Hill]

Chuck : You have presented us with 2 different problems. 
1. Engine pumping water and not overheating with the raw water seacock closed!?! 2 problems in one!
2. Running the engine running for 45 minutes at 2000rpm and not reaching operating temp - about 160degrees!?!

On #1 there is no way (from what you have said) that the water could be coming out of the exhaust with the seacock closed.  Maybe you or someone closed the seacock after you got back and forgot ???

On #2 even with a stuck open thermostat could the temperature not have come up to close to 160 degrees - after running 45 min @2000rpm.  Take a temperature gun sensor and get the engine block temperature. 
Also check the temperature wiring - brown wire attached to the temperature sender in the engine thermostat housing and check the attachment on the temp gage itself.

Make sure that the temp sender connection on the engine is NOT touching the metallic covering on the sound proofing under the lid/steps. If it is touching - that should give a higher temp not a lower temp reading, but check it anyway.

A bunch of thoughts.

[chuck53]

Chuck : You have presented us with 2 different problems. 
1. Engine pumping water and not overheating with the raw water seacock closed!?! 2 problems in one!
2. Running the engine running for 45 minutes at 2000rpm and not reaching operating temp - about 160degrees!?!

On #1 there is no way (from what you have said) that the water could be coming out of the exhaust with the seacock closed.  Maybe you or someone closed the seacock after you got back and forgot ???

There's only me and the wife.  She has never laid hands on any seacock and wouldn't know where to find them if I asked her to open/close one.
I can promise, the seacock was not open and water was pumping.  Was it a full flow?  Can't answer, but certainly enough to keep the engine from over heating.

On #2 even with a stuck open thermostat could the temperature not have come up to close to 160 degrees - after running 45 min @2000rpm.  Take a temperature gun sensor and get the engine block temperature. 

You're not reading my post.  The engine not heating up was when I was running the engine in my slip at 1000-1500 RPM's.  Once I got out on the water, running a steady 2000 RPM's, it got up to about 165-170 the whole time which is where it nomally runs.

Also check the temperature wiring - brown wire attached to the temperature sender in the engine thermostat housing and check the attachment on the temp gage itself.

Make sure that the temp sender connection on the engine is NOT touching the metallic covering on the sound proofing under the lid/steps. If it is touching - that should give a higher temp not a lower temp reading, but check it anyway.

I will check this out as well as inspecting/replacing my impeller.A bunch of thoughts.

[Ron Hill]

Chuck : Sorry about not remembering the low temp was in the slip with the engine running - that is somewhat normal at this time of year.

If you can close the seacock and you can remove the strainer and or take the hose off, and no water comes out - the seacock is working properly.
If you then open the seacock with the strainer off/loose or the hose off and water comes out - the seacock is working properly.

Now if you close that seacock and run the engine with a closed seacock and water still continues to come out of the exhaust - that doesn't compute and make no sense to me. 

[chuck53]

Now if you close that seacock and run the engine with a closed seacock and water still continues to come out of the exhaust - that doesn't compute and make no sense to me. 

That's why I'm so baffled.  When I get back to the boat in a few weeks, I'll try to figure this out.

[AT Phillips]

Chuck,
     Did you have any other seacocks opened?  Can't imagine that you can pump water out the exhaust, with every source of water closed.  If your certain that the engine seacocks was closed before the strainer, then another hose is connected past the strainer. 

I know it's a reach, but that would explain why you didn't overheat, & why you still have AF in the strainer.  v/r Adam
   

[chuck53]

Chuck,
     Did you have any other seacocks opened?  Can't imagine that you can pump water out the exhaust, with every source of water closed.  If your certain that the engine seacocks was closed before the strainer, then another hose is connected past the strainer. 

I know it's a reach, but that would explain why you didn't overheat, & why you still have AF in the strainer.  v/r Adam
   

All my seacocks are open except the one hooked up to the macerator pump.

The seacock in question has one hose from the seacock to the strainer and one hose from the strainer to the raw water pump.  No other hoses are connected in any way to the pump or hose leading to the pump.

[2ndwish]

Quite mysterious. There is one more thing that can cause water to come out the exhaust while the intake is closed, but it can't do it for very long- that is a leaking heat exchanger. There just isn't enough volume of AF in the manifold to supply 40 minutes of exhaust flow- so I doubt that's it. Just a thought though

Feel like I'm playing "Stump the Chumps"

[chuck53]

OK, back on the boat for the weekend.  Started the boat this morning with the seacock open.  Ran a few minutes just to warm it up a little.  While I can't actually see exhaust water coming out, I can hear it and see the exhaust water turbulence in the river water.
I shut down the engine, close my seacock (yes, the one attached to my strainer which is then connected to my raw water pump) and start the engine.  Again I can hear the exhaust water coming out and see the turbulence in the river.  A couple of seasoned sailing buddies are walking down the dock and I ask if they can see my exhaust.  They can.  While the engine is running at idle, I go below and open the seacock.  One buddy thought the volumn of exhaust water went up a little when I opened the seacock.  The other guy said he really couldn't see much difference.  Of course, the engine was at idle.  maybe it would have been different if I had revved up to 2000 RPM's.
The only difference I could see today out on the water under power was...2weeks ago while under power with the seacock closed, I ran a consistent 170 degrees.  Today, with the seacock open, I ran a consistent 160 degrees.

As I mentioned earlier, the only possible explanation I can think of is a partially defective seacock.  When closed and engine not running, it works and keeps seawater out of the boat, proved by the strainer being open and no water pouring out.  With the engine running, there must be enough suction by the water pump to pull adequate cooling water thru the closed seacock.

The real mystery is how can I run the engine at 2000 RPM's for 30 minutes and there still be anti freeze in the strainer.

I'm baffled!

[Ted Pounds]

Close the seacock and pull the hose off.  If water comes out you have a defective seacock (put the hose back on quickly  ).  If no water comes out then I'm stumped.   

[Stu Jackson]

The real mystery is how can I run the engine at 2000 RPM's for 30 minutes and there still be anti freeze in the strainer.

You have a 160F thermostat.

And there is no anti-freeze in the strainer, it's river water.

IIRC, you still haven't done a real test of your seacock by removing the hose from it to the strainer and testing the seacock.  If it was my boat, I'd get it next to a lift before I did that and be prepared for a short haul to replace the seacock.