Raw Water Exhaust - No Water Coming Out

[montenido]

Hi all, it has been a while since I posted, but I have been very busy fixing up Sundance. My latest venture involves the cooling system. It emitted very little water out the exhaust port before my intervention. Today I cleaned the sea water filter and changed the impeller on my water pump. I also used some rigid cable to ream out some cooling lines to insure that there were no restrictions. Well I must have knocked something loose which then lodged somewhere else because I now get NO water out of my exhaust. Believe me, I disassembled the water pump several times to insure that it was put together correctly and that it was pumping water - yes on both counts. I disconnected various water hoses and used a air pump for my inflatable to see if they were clear. All were clear except the one leading to the wet exhaust nipple. So, water goes in but does not come out the exhaust. Help! I am tired and could use some advice. BTW, I am very mechanical, just a bit stumped here.

Thanks, montenido

 

[Stu Jackson]

Good investigative work, so far...

So keep the analysis going, step by step. What's left is the HX and the exhaust riser connection and the muffler intake. Get to those and find out what's happening. I also recently had to use a dinghy pump to pump clear the raw water inlet through hull opening, so check to make sure you're getting enough water into the system from the rw intake.

 

[Glenn]

Start with the thru hull

to see if it is clogged. Next is the hose from the thru hull to the raw water strainer then to the raw water pump, then the out put side of the pump, then the hose to the HX. KLeep going til you get to the mixing elbow. My HX was clogged at the in take side, I could not see the clog with out a mirror, looked clean from the inside.

Could be the strainer is clogged.

 

[seanshine]

Air Bubble

You may possibly have an air bubble in front of the pump. If this happens, the pump receives no water. This has happened to me. You have to remove the hose to the pump and prime it with water.

 

[larryw]

No mention of

engine size/model. Be aware that the 5411 diesel spits out very little water. Other posters may be right, you could have an air lock. Prime all the hoses, and be sure you don't fill the aqualift muffler with water or it could backflow into the engine.

 

[tomfoolery]

Montenido - I may have missed something but....

Did you say you made sure the wet exhaust nipple as you call it is clear so cooling water can get from the heat exchanger to the muffler If you knocked something loose reaming out the HE it would likely lodge in the water injector nipple where the cooling water is mixed with the exhaust gases just ahead of the muffler as the fitting narrows, a chunk of salt reside could easily plug that.

Remember don't keep "trying" your engine with the raw water thru hull open as you could be filling up your muffler with water and if the muffler fills up the only place it has to go is into the exhaust/engine....

Like others have said you just have to meticulously follow the exhaust "chain" of flow from one end of the system or the other.

 

[Jack, La Paz, Mx]

Exhaust riser

If you have water going to the "nipple" in the exhaust, but not out the exhaust, then pull apart the exhaust riser and look inside. May be time to build another. Neither is a tough job. Like others have mentioned, don't crank the engine, pumping raw water into muffler without the engine firing and blowing the water out the exhaust. If the engine is not running, pumped water will flow back into the cylinders. Your water pump is working each time you turn over the engine.

 

[pbwdance]

From your thru hull for the sea water intake you can put a "T" in the line with a valve on both sides. So you have water entering the valve in the thru hull, it goes through a "T" which can be diverted to the engine for operation, or to the "T" which leads to a water hose connection. Every time before I start the engine (assuming its been a week or two), I run the water hose into the boat, connect to the "T" end, close off the secondary valve to the engine, open the "T" Valve and the gate valve and run water from the hose through the Thru hole. It clears all the junk out of your inlet so it wont get into the engine.

Paul

 

[Stu Jackson]

You can also blow back through the line

with a dinghy foot pump.