No water coming out of exhaust when engine running.

[Mike H.]

Our boat sat for about two months in the berth. When I ran it last water came out of the exhasut like it always does. When I started it up today, the exhaust had a hollow dry sound and no water was coming out. I check the raw water strainer, water flows into the boat no problem. Water flows to the raw water pump, I took the clamp and hose off and checked. I changed the impeller, and started the engine, still no water comes out of the exhaust. The impeller was fine. What could be the problem?

 

[kloudie1]

if you are sure you have water to the outlet of the pump, next, pull the hose off the exhaust elbow and have someone start the engine for a few seconds. If water is pumped out the hose, then the inlet fitting to the elbow or the elbow itself is plugged. If water does not come out, then the heat exchanger is probably plugged..

 

[Mike H.]

Thanks for the info. I pulled off the hoses and steel tubing down stream of the pump. Found a plugged test cock and some growth inside the tube. Not enough to plug anything. I'll look at the heat exchanger and elbow next as you instructed.

What is that steel tube and fittings in back of the engine? It has two small diameter tubes branching off to the block. Is that the heat exchanger? Or is the heat exchanger the large cast piece that holds the coolant?

And where is the thermostat? Is that a raw water thermostat or coolant thermostat?

Thanks again?

 

[Mike H.]

It's the elbow. I will remove it and attempt to clean it out.

 

[Don Crowther]

The heat exchanger is the large cast piece that hold the coolant. If you look for the temp probe at the front of the engine that's where the thermostat should be.Glad you found the elbow was plugged It can be a B-tch to clean out. Most i've seen on this site just buy a new one. But it can be done. Some take it to a rad shop or try sandblasting.
Good luck

 

[Mike H.]

The heat exchanger is the large cast piece that hold the coolant. If you look for the temp probe at the front of the engine that's where the thermostat should be.Glad you found the elbow was plugged It can be a B-tch to clean out. Most i've seen on this site just buy a new one. But it can be done. Some take it to a rad shop or try sandblasting.
Good luck

Thanks Don!
I brought the elbow, (with the other two elbows attached), home today. With a vise and large pipe wrench I removed the 3/4" thread x barb street ell and the 1 1/2" street ell. I found deposits clogging the 3/4" water jacket inside the mixing ell.

Before I broke them down, I blew through the 3/4" water ell and my breathe went through. Why water didn't go through I do not know. Did my breathe go through the water jacket and exit back through the exhaust? I don't know. I hope this was the problem.

I took the pieces and soaked them in straight muriatic acid for about two hours. They came out like new!!!!! No chiseling, scraping, brushing, sand blasting. It was too easy. I'll neutralize them in some baking soda after they are all clean.

I hope to hell this is the problem. Water pumped with good force up to the elbow last night. What else could it be?

I'll find out in two weeks after I reassemble the exhaust system.

Thanks again.

Mike

 

[Steve Dion]

Mike:

When you re-install everything, be sure that you coat all of the fittings with never sieze This makes taking the part apart again much easier. This goes for the bolts that screw into the block too.

 

[Mike H.]

Mike:

When you re-install everything, be sure that you coat all of the fittings with never sieze This makes taking the part apart again much easier. This goes for the bolts that screw into the block too.

Thanks Steve:

I plan on getting some anti sieze cream and using it.

I'm glad you responded. You have the same boat as mine. Have you experienced the same problem with the exhaust elbow? How often do you clean your's out? Do you just replace your elbow?

And on a different note, do you remove your starter to R&R your water pump impeller?

Thanks,

Mike