Broken down in Anacortes with cooling issue, help appreciated

[Antares]

If you are at a dock you can try back flushing the thru hull with a water hose. I have had that work. Once you start getting good flow thru the water pump">raw water pump keep working towards the exhaust elbow to find the point the flow is restricted. It's a bit messy but you can rinse with everything with fresh water when done. The exhaust elbow is another potential problem area. They can get carboned up or fail internally. I spent the better part of one vacation chasing a similar cooling problem. Good luck.

[1affiah]

Hey, Congatulations! You earned that beer!

[Uncle Bob]

Originally Posted by Heck

The seacock for the intake is a bit of mess and I'm not confident I should take it all apart without having replacement parts on hand. However after confirming that no diver was going to come for several days I grew bold and was able to remove the strainer mount.

Then I had clearance to get a water hose shooting right into the thru hull and with a few seconds whatever blockage was there was gone. Now when I open the seacock water gushes in, as opposed to a trickle. I started the engine and water gushes out, even at idle. Now a beer and a shower. Thanks everyone for your help.

[keepondancin]

I had the same engine in a Catalina 34, in the 80’s. I seem to remember that it has a tendency to get an air lock in the cooling system, if coolant level get’s low. I do forget exactly how to force the air out, but you might find info on a Catalina owners forum. This is for future reference, as it sounds like you resolved the issue. You can also use a dinghy air pump, if you have one, jammed in the water hose with rags stuffed around it to try to blow blockages back ou the thru Hull.

[japarker11]

Wow, that was a lot of work for a wayward plastic baggie or kelp! Guessing the exterior of the thru hull is the bronze sloping strainer type which often will grab a baggie or kelp and partially suck it into one of the slotted openings. I clear it by going astern at good throttle setting as the prop wash will be directed at the offending thru hull. If the restriction remains, repeat with with the seacock closed. A GoPro on a boat hook has worked in identifying such gremlins. And, there aren't any kelp beds in the Anacortes area[emoji16]. Hope you are enjoying the best social distancing.

[LittleWing77]

Originally Posted by Heck

The seacock for the intake is a bit of mess and I'm not confident I should take it all apart without having replacement parts on hand. However after confirming that no diver was going to come for several days I grew bold and was able to remove the strainer mount.

Then I had clearance to get a water hose shooting right into the thru hull and with a few seconds whatever blockage was there was gone. Now when I open the seacock water gushes in, as opposed to a trickle. I started the engine and water gushes out, even at idle. Now a beer and a shower. Thanks everyone for your help.

This is GREAT news!!!

What a great feeling, eh? An anxiety turning into a triumph!

Well done,
LittleWing77

[Cheechako]

Originally Posted by Heck

The seacock for the intake is a bit of mess and I'm not confident I should take it all apart without having replacement parts on hand. However after confirming that no diver was going to come for several days I grew bold and was able to remove the strainer mount.

Then I had clearance to get a water hose shooting right into the thru hull and with a few seconds whatever blockage was there was gone. Now when I open the seacock water gushes in, as opposed to a trickle. I started the engine and water gushes out, even at idle. Now a beer and a shower. Thanks everyone for your help.

Great!

[redhead]

If the problem comes back we will be in Anacortes on Tues the 4th. My mechanic husband could take a look, lord knows we've been helped often enough...

[Exctyengr]

Congratulations on the fix. Yes you earned that victory beer!

[Cadence]

Originally Posted by Heck

We were cruising in the San Juan Islands for several days and everything was working fine with a healthy exhaust and temperature gauge down the middle, 170-180 degrees. Late one afternoon while anchoring the engine temperature gauge started climbing while also showing white steam from the exhaust. Boat is an 1989 Catalina 36 with a Universal M-25XP engine and is new to me so I have little knowledge of pre-existing issues.

First thing I tried was cleaning the intake raw water strainer which was kind of dirty so I thought that was that. Next day started motoring and after a few minutes engine started overheating again. We were in a bad spot due to conditions and to cut a long story short anchored in the closest protected shore and called for a tow. Eventually got to Cap Sante marina in Anacortes. Another long story for another day.

After getting to a dock I confirmed there was almost no water coming from the exhaust through-hull, just steam.

Things I have tried since then:

Raw water impeller. Looks in good shape and is intact and flexible although pump overall could be refreshed. Added some grease to center of impeller on cover side. I have an extra impeller but doesn't seem I can change it without a press. I have confirmed that water does come out of the pump however doesn't seem like it's a lot. Should the water volume increase with rpm?

Heat exchanger. I have the 3" Universal version. Took it apart and the section with the drain showed lots of zinc debris and blockage. Soaked it overnight in Coca-Cola. In the morning cleaned all the crud and ran lots of fresh water. There's now a good flow of water through every connection. Zinc is around 30% so needs to be replaced very soon as well as gaskets. No leaks.

Exhaust. Unplugged the hose that takes raw water to the exhaust manifold and put a hose there. Run water and confirmed it flows well to the exhaust through-hull.

Refilled the system with coolant and ran the engine for a while. Added coolant again. Repeated a couple of times until coolant level stayed consistent.

There's is now water coming out of the exhaust when the engine runs, however it does look like less than normal. When water comes out, every 5-6 seconds, it gets sprayed out, does not stream.

If I idle the engine at 1000 rpm and neutral the temp stays around 180F. However if the engine is under load the temperature starts climbing slowly but steadily and after you get to 190F steam starts to appear. Higher rpms will produce more frequent water discharge from the exhaust.

Any ideas appreciated! Mechanics are all at least a week out so I'd also love referrals to professionals that can help in the near future.Thank you!

You sound very thorough. I didn't see a swim to check a fouled intake?

[jakkum]

Originally Posted by Heck

We were cruising in the San Juan Islands for several days and everything was working fine with a healthy exhaust and temperature gauge down the middle, 170-180 degrees. Late one afternoon while anchoring the engine temperature gauge started climbing while also showing white steam from the exhaust. Boat is an 1989 Catalina 36 with a Universal M-25XP engine and is new to me so I have little knowledge of pre-existing issues.

First thing I tried was cleaning the intake raw water strainer which was kind of dirty so I thought that was that. Next day started motoring and after a few minutes engine started overheating again. We were in a bad spot due to conditions and to cut a long story short anchored in the closest protected shore and called for a tow. Eventually got to Cap Sante marina in Anacortes. Another long story for another day.

After getting to a dock I confirmed there was almost no water coming from the exhaust through-hull, just steam.

Things I have tried since then:

Raw water impeller. Looks in good shape and is intact and flexible although pump overall could be refreshed. Added some grease to center of impeller on cover side. I have an extra impeller but doesn't seem I can change it without a press. I have confirmed that water does come out of the pump however doesn't seem like it's a lot. Should the water volume increase with rpm?

Heat exchanger. I have the 3" Universal version. Took it apart and the section with the drain showed lots of zinc debris and blockage. Soaked it overnight in Coca-Cola. In the morning cleaned all the crud and ran lots of fresh water. There's now a good flow of water through every connection. Zinc is around 30% so needs to be replaced very soon as well as gaskets. No leaks.

Exhaust. Unplugged the hose that takes raw water to the exhaust manifold and put a hose there. Run water and confirmed it flows well to the exhaust through-hull.

Refilled the system with coolant and ran the engine for a while. Added coolant again. Repeated a couple of times until coolant level stayed consistent.

There's is now water coming out of the exhaust when the engine runs, however it does look like less than normal. When water comes out, every 5-6 seconds, it gets sprayed out, does not stream.

If I idle the engine at 1000 rpm and neutral the temp stays around 180F. However if the engine is under load the temperature starts climbing slowly but steadily and after you get to 190F steam starts to appear. Higher rpms will produce more frequent water discharge from the exhaust.

Any ideas appreciated! Mechanics are all at least a week out so I'd also love referrals to professionals that can help in the near future.Thank you!

Sometimes, the impeller looks all right, but the metal center can turn inside the rubber. Already had that twice. Just try the new one you have.

[larsfforsberg]

Head gasket?

[Flatswing]

[QUOTE=LittleWing77;3200037]Geez does anybody read anymore?!

The FIRST thing the OP did was check and clean his raw water intake and strainer!

I would have agreed until this week. Filled my ac strainer with puff mud at low tide. Cleaned and flushed the strainer as usual: AC ran but water flowed in fits & starts - not the usual steady stream. Close inspection -sucking air through strainer cap even though it was tight. Turned out, I hadn’t thoroughly cleaned the fine mud From the O ring. Quick clean, dab of silicone grease and water flow back to normal. So I would still check for leaks at the strainer and anything clogging the external screen.

[northwestsailor]

I had a bad seal on my raw water strainer. Took a long time to find it. Replaced the O ring and all was well in a hurry. It was nice to check all the other suspicious items ie impeller, exchanger etc but could have saved a bunch of time getting right to the problem.

[Yellowjacket]

You are to be congratulated. That was a difficult job, and a bit harrowing to get to where you could deal with it. You now have a system that's refreshed, and without the bit of kelp I'd bet was sucked part way up your through-hull.

I'm over in Friday Harbor, if you are coming this way, on board a blue boat in the channel, "Foxy." Would be pleased to meet you.

~ Yellowjacket.