No water flow to exhaust on my Universal 5432

[RodrigoDC]

I have a Universal M-40 engine is misbehaving. No water flow going out of the exhaust. These are the steps I've already taken:

1. I replaced the impeller, although the old one was in pretty good shape.
2. I opened the sea cock strainer while slowly opening the sea cock to see if there was sea water flowing in. It does, although is more a trickle, not exactly gushing out. Should water rush out immediately upon opening the sea cock?
3. I cleaned the heat exchanger by opening both side caps and clearing any debris there. I have not removed the HX yet, just opened both side caps.
4. I have disconnected hoses up to the HX and water flows, again a steady stream, but certainly not gushing out while leaving the sea cock open (and the engine off).

Despite the above, still no water is coming out from the exhaust.

Questions:

1. Should water flow with pressure when opening the sea cock and leaving the engine off?
2. I was told perhaps the thermostat is at fault. For the life of me, I cannot find it on my engine. Could you point me in the right direction to find it?
3. What would be the best way to try to clean the through hull while the boat is on the water?
4. I would expect the boat to have a muffler, but unless I have no idea what I'm looking for, I cannot find it. Is a muffler a must on all boats?
5. Oil is overdue for a change. Could replacing the oil help in solving this issue?

If you need me to send pictures or videos, I'll be happy to, but I thought to start with this.

Thank you in advance,
Rodrigo

 

[sail sfbay]

Welcome to the forum!!

Same issue came up on this thread No water coming out of exhaust when engine running. | Sailboat Owners Forums. I would next inspect the mixing elbow and exhaust hose for blockage, and replace if necessary.

 

[DeniseO30]

The very very first thing to determine and make sure and it seems like you already found; there is not enough water gushing from or into to sea valve you can disconnect the hose right there with the valve off then open the valve, you should get an alarming rate of water if not, the strainer on the bottom may have weeds scum or even plastic bags over or in it.

It's kind of like checking to see if something is plugged in you always check the very first thing in this case it's your water source.
It's human nature to start looking at the most complicated things first instead of the simple things,
If you have an oberdorfer
pump you have to be very sure you have the correct in impeller, I made the mistake of getting the blue run dry type and they weren't quite wide enough to make it self priming.

 

[JoeWhite]

Disconnect the input hose to the raw water pump and place it into a 5 gallon bucket of water, run engine. How is the water flow. That will point which half is the problem.

 

[DeniseO30]

Disconnect the input hose to the raw water pump and place it into a 5 gallon bucket of water, run engine. How is the water flow. That will point which half is the problem.

2.5 gpm if I remember correctly

 

[RodrigoDC]

Aha, see, this is why I love this forum.

I just didn't know what the correct water flow rate should be. Water definitely runs all the way to the heat exchanger with the engine off, but it's definitely not 2.5 gal/minute, at least not when the engine is not running.

I have a Sherwood pump, and it appears to be working fine. The old impeller was in very shape, even though I replaced it last year.

I will dive under the water line to check on the through hull for the raw water intake and try to clean it as best as possible. I'll report back if the flow crate increases. I hope it's as simple as that.

Thanks again to all.

 

[Tally Ho]

It sounds like you may have an obstruction in the thru-hull. If you “are only getting a trickle” of the thruhull with the valve open, something is blocking the valve or skin fitting.

I assume where you checked is below the water line…and if so, you should be thinking that you could sink your boat pretty quickly with the valve open and no hose attached….a trickle indicates something is blocked in the valve or thru hull.

Nothing will have flow after that point.


Greg

 

[DeniseO30]

Aha, see, this is why I love this forum.

I just didn't know what the correct water flow rate should be. Water definitely runs all the way to the heat exchanger with the engine off, but it's definitely not 2.5 gal/minute, at least not when the engine is not running.

I have a Sherwood pump, and it appears to be working fine. The old impeller was in very shape, even though I replaced it last year.

I will dive under the water line to check on the through hull for the raw water intake and try to clean it as best as possible. I'll report back if the flow crate increases. I hope it's as simple as that.

Thanks again to all.

Quite often the intake water strainer for the engine is at or near the water line of the vessel. I think it's done that way so you
flooding the boat when you open the the strainer and forget to close to sea valve.

Oh and water mufflers are nothing like automotive mufflers they are made of plastic and fiberglass just follow that big exhaust hose off the back of the engine you should be able to find your muffler.

If all else fails disconnect the water connection where it goes into the exhaust elbow see if you have water flow there but you can't really check it by running the engine, it would be a mess!

 

[Sailgunner]

I sometimes get sea grass stuck in my intake before the intake valve. I disconnect my sea water line at the engine and use my dingy foot pump and blow water back through the system. Works great.
The other thing that can happen is an air bubble somewhere before the engine. Again at the engine before the water pump water should be pouring out. I can usually take care of the air bubble there by lowering the line.

 

[dlochner]

I opened the sea cock strainer while slowly opening the sea cock to see if there was sea water flowing in. It does, although is more a trickle, not exactly gushing out. Should water rush out immediately upon opening the sea cock?

This is likely the problem. The sea cock is clogged. There should be geyser of water coming up through the seacock with the hose removed and the seacock opened.

Here's an article on the issue from MaineSail.

External Strainers OMG - Marine How To

"RC My Engine is Overheating?" Over the years I have really grown to distrust and dislike external intake strainers of either the scoop type or the non directional (sailboat style) round type. The real danger in these devices comes when you have a blockage and can't get to the crud to clean it.

marinehowto.com

 

[RodrigoDC]

Wonderful suggestions. I'll try to connect a water hose into the out take of the strainer to try to push whatever it is clogging back out.. If that doesn't work, then I'll dive and clean from the hull. But it ain't fun to dive in November in Annapolis.

Thank you all. Wonderful ideas!

 

[dlochner]

Wonderful suggestions. I'll try to connect a water hose into the out take of the strainer to try to push whatever it is clogging back out.. If that doesn't work, then I'll dive and clean from the hull. But it ain't fun to dive in November in Annapolis.

Thank you all. Wonderful ideas!

Before you dive, get a piece of hose that will extend from the thruhull to above the waterline, hopefully in a straight line. Attach this hose to the seacock. Use a long thin rod to push down through the hose and open seacock. This may remove anything that has grown or become captured in the external strainer or in the through hull. A long welding rod may be adequate. If you need a longer rod, use some all thread and a connector. The rod should be thin, ⅛" would be good because there may be an external strainer with small holes.

 

[PaulK]

We just hauled and found our intake strainer had barnacles all over it, including the insides. Had to remove it, clean them all off and poke around in the intake hole with a screwdriver to get the ones that were growing in there too. Can easily understand how water flow could be almost stopped by a season's growth.

 

[RodrigoDC]

Ok, I finally had a chance work on my boat today. To recap, no water was coming out from the exhaust, and there was very little water flow coming from the raw water intake valve.

So, I connected a garden hose with plenty of pressure into the strainer intake while the valve was closed. I opened the valve at the same time I opened the garden hose valve, and sure enough, stuff came out to water from under the hull. Water was finally gushing in, with plenty of pressure.

Good news, right? I thought, that's it, all is good, but no, still not a drop of water was coming out of the exhaust.

I disconnected the hose going into the heat exchanger, and you can see in the attached video that water is flowing into it with the engine off at a rate that I would imagine is reasonable. But still, no luck.

Any other suggestions? Could my water pump be dead? Could the thermostat be failing? If so, can anyone point me where the tstat may be located in my Universal m-40? Any other options?

Thank you in advance.

 

[Sailgunner]

I think you should have more flow than you do. Still may be an air bubble somewhere in you intake or an obstruction between your engine and intake.

 

[DeniseO30]

Bypass the strainer? See if the strainer basket is installed upside down, follow the hoses to the inverted Loop or siphon breaker (mine was clogged) I had to replace it. Crank the engine but don't start it, see if water comes out the discharge before the heat exchanger. Garden hose pressure will blow out the seals on your impeller pump so you don't need to do that, maybe a hose is clogged somewhere along the way or it's kinked, just take every part of it apart it's a simple cooling system more pictures will be helpful.
Because you're asking if the thermostat and motor pump are bad possibly you're very confused maybe you should get some help with someone more knowledgeable? the raw water system cools the coolant in the heat exchanger but doesn't mix with it, think of the heat exchanger as a radiator but instead of a fan there is seawater cooling the "radiator"

 

[BAD ORCA]

You have probably fixed this by now, but dont forget the elbows going into and exiting the strainer. Mine were so clogged there was barely an opening. Everyone seems to forget them. Also that water flow is pretty weak in the video. I have same engine/setup.

 

[RodrigoDC]

You have probably fixed this by now, but dont forget the elbows going into and exiting the strainer. Mine were so clogged there was barely an opening. Everyone seems to forget them. Also that water flow is pretty weak in the video. I have same engine/setup.

Actually, I am yet to fix this issue. I am going to diassamble each and every part of the entire system.

But your idea to check on the strainer elbows is a good one.

Thanks a bunch.

 

[BAD ORCA]

Its also possible your thru hull seacock is broken/degraded and is not opening all the way. I had the exact same issue as your dealing with now. My boat is a 1980 boat and the neglect and wear and tear built up over the years. My waterflow problem was several issues. The first was that the seacock handle was turning the internal ball valve but it was only opening the ball about 1/4 of full open. I had no idea and would not have noticed until one day i just yanked the hose off of the connector and looked at it with a flashlight. Water should gush out in a small geyser when the hose is disconnected and the thru-hull is opened.

The second problem was the elbows going into and exiting the strainer. After almost 40 years they were almost completely clogged with hardened marine growth. I had to pull out the strainer and rebuild it. I replaced the elbows with new bronze elbows from Groco.

Third problem was old/semi clogged hoses. pulled them all out and replaced them all.

Fourth was clogged heat exchanger. Broken zincs and debris built up over the years. I removed it and soaked it in Barnacle Buster for a day. I rebuilt it, replaced rubber end caps and zincs and re-installed.

This is probably not necessary but i also removed the old scoop style thru-hull and replaced it with a Groco strait cut away thru hull. No more flow impediment from marine growth and easy to ream out with a wood dowel from inside the boat. Also replaced the water lock muffler and all the exhaust hoses with new. I doubt either of these is necessary but i did it since all mine were original 40 years old.

After all this my flow problems were solved and engine ran actually a little cooler than 160 thermostat. Water flow out the exhaust is perfect.

If all that fails i think the only other problem it could be is a damaged raw water pump or clogged exhaust elbow, but from your video, the problem is clearly before the elbow.

Your thermostat is part of the internal engine cooling system. As mentioned its not directly connected to the raw water cooling system on your Universal M40. They bypass each other in the heat exchanger where the raw water cools the antifreeze but they are seperated by sealed copper pipes. They never actually mix. A bad thermostat could cause your engine to overheat but raw water flow is equally important, maybe more-so. If your engine overheats after you have fixed your raw water flow issue then its possible there are other issues with the internal cooling system.

 

[RodrigoDC]

I'm following up with my water flow issue. Still no solution.

Here's what I have done:

1. Water is gushing in from the raw water through hull valve. That's not the issue.

2. Each hose segment has been cleaned, replaced, or tested for water flow. No issues there.

3. I took the heat exchanger (HX) out and had it professionally cleaned and flushed at a radiator shop. While at it, I replaced the end cap gaskets. No leaks, no issues there.

4. There are no clugs in the mixing elbow.

5. As previously stated, I replaced the impeller.

6. I disconnected the Sherwood water pump out take hose and started the engine. There was no significant water flow rate increase between when the engine was off and when it was running.

7. I placed a garden hose into the hose that connects to the out take Sherwood water pump, and sstarted the engine, and sure enough, water flows all the way out to the exhaust.

So, given what I have stated, especially in paragraphs 6 and 7, my assumption is that the Sherwood pump is not working (i.e., not turning the impeller).

I have purchased a used Sherwood pump and will replace it hopefully Tuesday night, and if all goes well, that will solve the problem.

Here are my questions based on my very limited understanding of how the pump interacts with the engine.

1. Is it possible that the Sherwood pump is fine, but an internal engine cam or belt or anything that turns the pump could be at fault? If so, what then?

2. The current pump, has a cam that connects to a metal rod in the engine via an metal adaptor. Should these fit like a globe, or is it normal to have some play among them?

Anywho, I hope the new pump will do the trick, but I'm all ears for advice.

Thanks in advance!