Catalina 30, Universal M25 - No water running from the exhaust, issue with overheating. Please help!

ChrisVR1994

ChrisVR1994

.
Feb 1, 2024
20
Catalina 30 Seattle
Hi there:

I recently saw when I started my engine that there was no water being expelled from the transom port. I assume I have a cooling issue and have checked the raw water pump and removed the heat exchanger. It seems that all the blades of the impeller are there and the heat exchanger has some, but not a ton of debris inside (I have the 3'' x 13'' model). Any suggestions? I'm about to install a strainer, could use some advice on which model and also installation. I'm hoping it's not the exhaust elbow!

Thank you for your help.
 

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jssailem

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,078
CAL 35 Cruiser #21 moored EVERETT WA
I would take the following actions.
  1. Examine the raw water inflow for any clogging from the through hull to the water pump.
  2. Replace the impeller.
  3. Examine the water pump for any weeping (there appears to be some corrosion - green deposit) on the lower part of the outside of the pump. If this is from the weep hole then there is a seal problem. Two options. Service the pump - install a new seal - or replace the pump. Clean the surface of the pump before putting the cover back. Do not forget the thin gasket.
  4. Check the hoses from the pump to the heat exchanger for condition and any leaks.
  5. The heat exchanger can be cleaned of debris and a new zinc installed. I would take the HE to a radiator shop and ask them to clean it and pressure check it. When I did that a few years ago, it was about $65 and completed in 4 days.
  6. If you are looking for a strainer the Groco ARG-750 is a good one. Check the size of your hose from the through hull to the strainer. The 750 is 3/4" ID hose.
Assemble all the parts and then test them for flow.

If lack of exhaust water is still an issue, then look at your Exhaust Elbow.
 
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Rich Stidger

Rich Stidger

.
Feb 10, 2004
4,125
Hunter 40.5 Warwick, RI
jssailem said:
I would take the following actions.
  1. Examine the raw water inflow for any clogging from the through hull to the water pump.
  2. Replace the impeller.
  3. Examine the water pump for any weeping (there appears to be some corrosion - green deposit) on the lower part of the outside of the pump. If this is from the weep hole then there is a seal problem. Two options. Service the pump - install a new seal - or replace the pump. Clean the surface of the pump before putting the cover back. Do not forget the thin gasket.
  4. Check the hoses from the pump to the heat exchanger for condition and any leaks.
  5. The heat exchanger can be cleaned of debris and a new zinc installed. I would take the HE to a radiator shop and ask them to clean it and pressure check it. When I did that a few years ago, it was about $65 and completed in 4 days.
  6. If you are looking for a strainer the Groco ARG-750 is a good one. Check the size of your hose from the through hull to the strainer. The 750 is 3/4" ID hose.
Assemble all the parts and then test them for flow.

If lack of exhaust water is still an issue, then look at your Exhaust Elbow.
Click to expand
All good advice. If the pump functions, then your problem is a blockage somewhere. Take it step-by-step to find and eliminate the problem. If your memory is as bad as mine, take notes as you go along to document your observations.
 
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M

MikeO53

.
Feb 11, 2017
35
Last year, I had 2 different new impellers with the same problem (both were new). The bronze center is supposed to be glued to the rubber vanes of the impeller but we're not. When inspecting the impeller, it was not obvious there was a problem as it looked perfect. The problem was the center bronze piece was spinning but the outer rubber was not - thus no water output and overheating.
Another thing to be aware of is the original engines came with a 2" heat exchanger. A bulletin was posted by Westerbeke years later advising owners to upgrade to a 3" diameter heat exchanger - my temperature went from 180-190 down to around 140 degrees.
 
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Bob S

Bob S

.
Sep 27, 2007
1,803
Beneteau 393 New Bedford, MA
I replaced the water pump last season. On the 393 it is easier to remove the whole pump to replace the impeller. I sent the old pump to Depco to be rebuild. They told me the internal housing of the pump was worn too much to repair. When its worn it severely limits water flow. It was 20 years old with 1000 hours on it. John’s trouble shooting is spot on.
check out “Maine Sail’s how to“ site here. He has a tremendous amount of information. Rebuilding A Perko Bronze Sea Strainer - Marine How To
i replaced the strainer on my Catalina 30 with his recommendation. Had a Catalina 30 for ten years, great boat!
marinehowto.com

Rebuilding A Raw Water Pump - Marine How To

Pump Removed This article is going to assume you have the skills to safely and easily remove your own water pump from the engine. This one is easy and uses four bolts and a gasket to mount to the timing gear
marinehowto.com
 
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Stu Jackson

Stu Jackson

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Feb 26, 2004
23,030
Catalina 34 224 Maple Bay, BC, Canada
Raw water pump faceplate must be smooth. I had my Oberdorfer faceplate refaced. I had the old really thick one. The new thinner faceplates on sale now do not work on old pumps, the four holes are slightly different. That's why I had to have it refaced at a machine shop. 1986 boat.

You don't need a strainer between the pump and the HX. My boat is almost 40 years old, I've had it since 1998. You do need one at the inlet seacock.
 
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Richard19068

Richard19068

.
Jun 11, 2004
1,760
Oday 31 Redondo Beach
ChrisVR1994 said:
Hi there:

I recently saw when I started my engine that there was no water being expelled from the transom port. I assume I have a cooling issue and have checked the raw water pump and removed the heat exchanger. It seems that all the blades of the impeller are there and the heat exchanger has some, but not a ton of debris inside (I have the 3'' x 13'' model). Any suggestions? I'm about to install a strainer, could use some advice on which model and also installation. I'm hoping it's not the exhaust elbow!

Thank you for your help.
Click to expand
In your second picture it almost looks like there is a plastic bag or something in the right two chambers of the HX.
Is that just an illusion I am seeing?

1748577775797.png
 
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Scott T-Bird

Scott T-Bird

.
Oct 26, 2008
6,266
Catalina 320 Barnegat, NJ
Even when the blades look perfect the impeller could be failing. In 20 years of boat ownership, I have yet to find a failed impeller that had missing or broken blades. They always look like they just came out of the box. But they still don't work and replacing the impeller always cures the matter. In 20 years, I've replaced maybe 6 or 7 impellers. But you should check the usual suspects as well. Open the seacock with the hose removed to make sure the thru hull isn't clogged and move systematically towards the exhaust. My original boat had a 90 d bend at the hose connection to the seacock. It routinely was clogged with sea grass and it was a real nuisance to clear at times.

Just looking at your pics, the exchanger looks downright awful to me. I've never seen one looking that clogged and @Richard19068 is right about whatever plastic appears to be inside. It looks to me like you absolutely need an on-board strainer in line between the seacock and the raw water pump (not just a cover on the exterior side of the hull). Whatever is getting pumped thru the exchanger looks really bad.
 
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ChrisVR1994

ChrisVR1994

.
Feb 1, 2024
20
Catalina 30 Seattle
Richard19068 said:
In your second picture it almost looks like there is a plastic bag or something in the right two chambers of the HX.
Is that just an illusion I am seeing?

View attachment 231797
Click to expand
It’s seagrass and crud. Definitely a mess behind the gaskets on both sides. Debating replacing with a new heat exchanger or having it professionally cleaned and pressure tested
 
Richard19068

Richard19068

.
Jun 11, 2004
1,760
Oday 31 Redondo Beach
ChrisVR1994 said:
It’s seagrass and crud. Definitely a mess behind the gaskets on both sides. Debating replacing with a new heat exchanger or having it professionally cleaned and pressure tested
Click to expand
New ones are expensive. Professional cleaning and pressure testing would be a good start but if you are handy you can try to clean it out yourself.

Take it off, remove the obvious gunk, flush it out with a garden hose, get a wooden dowel just a tad smaller than the tubes and gently rod them out. You will feel some resistance from the build up but don't force the dowel. If it doesn't go through try a smaller diameter dowel. If that goes, run it up and down a few times and then see if the bigger dowel goes through. You could also soak the whole thing in a mild acidic solution to help dissolve some of the calcium build up up before running the dowel through the tubes. With some clever DIY plugs and hose attachments you can even do a rudimentary pressure test yourself (just don't over pressurize it).

Of course having a professional do it is easier but if we relied on professionals to do everything on our boats most of us would be broke. Hmm... maybe most of us are broke anyway.
 
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JoeWhite

JoeWhite

.
Mar 6, 2008
1,325
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
ChrisVR1994 said:
I’m not sure. Is there a way of removing and cleaning, or you have to replace the entire thing?
Click to expand
To check if it is clogged, disconnect the hose and put it in a gallon bucket and have someone turn on the engine for 10 seconds and see if you get ample water flowing into the bucket. If there is plenty of water flow then remove and clean the water injector portion only.
 
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Hayden Watson

Hayden Watson

.
Apr 5, 2009
3,119
Catalina '88 C30 tr/bs Oak Harbor, WA
Your heat exchanger is completely plugged based on the photos you sent. It is a 4-pass design so that all of the water flows through each of the four quadrants. It runs from starboard, to port, to starboard and back to port before heading to the mixing elbow.

The 12 to 3 and 3 to 6 quadrants are totally blocked and the 6 to 9 is mostly blocked. Only the 9 to 12 quadrant could be said to be mostly clear. You can test the flow by standing it on vertically and pouring water into the end. The water should pour right through.

The simple and best way to clean it is to take it to a radiator shop and have them boil it out and pressure test it.
 
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Rich Stidger

Rich Stidger

.
Feb 10, 2004
4,125
Hunter 40.5 Warwick, RI
If I can do it myself with confidence that the job will be done correctly and with quality, I will not hesitate to do it.
I hate paying $125++ to someone who is just doing a job for something I can do.
But if a special tool or skill is needed, I do hire a pro.
 
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Hayden Watson

Hayden Watson

.
Apr 5, 2009
3,119
Catalina '88 C30 tr/bs Oak Harbor, WA
I have owned my C30 for 27 years and the heat exchanger has needed to be cleaned twice. The first time I had a radiator shop do it and then charge me $80. The next time I needed it, I called them up and they said it would be $200 minimum and maybe more depending on what they found. I did it myself.
 
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