"Cooling Water Temp." Warning

[Joe Myerson]

As the New England sailing season draws to a close, my ancient 1GM has started acting up intermittently. I'm hoping it is not a serious problem.

Here are the symptoms:

A few weeks ago, as I was on my way back to the mooring, the "CW Temp" warning light and alarm sounded. I turned off the engine, coasted to the mooring, grabbed my manual and determined that "CW Temp" stood for "Cooling Water Temperature." (Doh!).

While on the mooring, I turned the engine on again, and no alarm. I increased the idle speed, still no alarm. Then I put the engine in reverse on the mooring -- at low rpm -- and again, no alarm.

Today, as I was heading out into Buzzards Bay for one of the last sails of the season, the alarm sounded again. As I was reaching for the cutoff switch, the alarm stopped. I used the engine to get out to the bay, sailed for several hours and motorsailed back (the wind was light).

Once again, as I was approaching the mooring, the alarm sounded. I cut the engine and managed to coast back to the mooring (there was no wind). After securing the boat and tidying up, I decided to start the engine again.

And it started with no alarm.

I'm hoping it's something relatively benign -- like a thermostat or, even better, a bad impeller or loose belt.

Any suggestions?

Thanks,

--Joe

PS sure wish I could get to Havre de Grace, but it's not in the cards this year.

[Dean Abramson]

Joe,

Did you have the normal amount of water coming out of the exhaust pipe???

First I would check the impeller. The rubber part may have separated from the center metal part, but that will not be immediately obvious visually. Grab the engine belt and turn the engine while watching the impeller; see if the center is turning independently of the vanes. Or, more obvious, vanes may be missing.

If that is not conclusive: close the seacock, remove the water intake hose at the water pump, then open the seacock momentarily and see if water gushes in. if not, the hull strainer or the hose is clogged with crap. So then remove the hose at the seacock, and try again; if it does gush this way, the problem is a clogged hose.

I am guessing an impeller problem.

Better minds out there can tell you how to test a thermostat in a pot of water on the stove. I do not remember offhand what temp it is supposed to open at.

Good luck,

Dean

[Warren Kaplan]

Also, exhaust elbows have a finite life span before they corrode. Once they corrode from the inside, which may not be visible from simple outside inspection, it can cause all kinds of problems with overheating due to clogging.

In the years I've had my CD27 I've had to replace my exhaust elbow twice. About once every 4 to 5 years.

[Joe Myerson]

Dean and Warren:

Thanks for your input.

Dean -- my guess is that it is probably the impeller. When the engine was running fine on the mooring, I was able to lean over the stern and watch the normal flow of cooling water coming out of the exhaust.

When the alarm was sounding, I was under way and concerned about frying the engine, so I pulled the shutoff valve before I had a chance to look over the transom.

Warren -- I replaced the exhaust elbow almost exactly five years ago. If what you say is true, it might be time to check it out again.

I'm due for haulout soon, but I will have to sail/motor from my mooring to the boatyard. Yesterday, with its light winds, would have been perfect for that, but I was hoping to squeeze out one more week of sailing. I guess I was being greedy.

--Joe

[mahalocd36]

Since it seems to be happening near your mooring, is there something in the anchorage that's getting sucked into your water filter blocking water flow? (i.e. seaweed)

[Joe Myerson]

Thanks Melissa,

That was my first thought, but there isn't much seaweed in that particular area.

However, I'm wondering if there are perhaps enough barnacles built up on the raw-water intake so almost anything could reduce the flow of cooling water.

I don't have a wetsuit, and the water has turned coooold (well, you Mainers would probably still consider it warm--but of course it's only outtah-statahs who actually swim in Maine water).

I'll certainly have that checked at haul-out.

This has been a brutal year for the growth of barnacles and (yechchch) sea squirts, judging from dock pilings and my dinghy.

--Joe

[CruiseAlong]

Joe,
Don't rule out the temperature switch itself is starting to be faulty. There appears to be too much alarm/no alarm random activity to indicate that a real big problem exists.
Dana

[Gary M]

Years ago I was starting a trip to Catalina Island and my temp alarm went off.

Sea Tow brought me back to my slip and I watched my mechanic trouble shoot the problem.

He started the engine and let it warm up. When it had time to warm up he touched it with his had and counted 1001,1002 1003. He could leave his hand on the engine for a count of about 3 seconds.

He then raised the idle speed and repeated.

After about 30 minutes or so, he replaced the sending unit for the heat gage and I left for Catalina the next day.

So for what ever that's worth!

Gary

[Michael Abramson]

Hi Joe,

Here's a tip if you find the water flow through the seacock is restricted.

I learned this the hard way, after stupidly painted over the holes in my inlet strainer, planning to open the holes later with an icepick, but of course I forgot to do so. Once the boat was launched, I had no raw water flow.

I removed the hose from that seacock, with it closed of course. I clamped the wrist opening of an old rubber glove around the seacock. Then I inserted a long piece of steel rod through one of the finger tips, and used a plastic tie around that to seal the finger to the rod. The rod had been ground down at the tip so it would easily go through the openings in the strainer.

Then I opened the seacock, the rubber glove filled with water and dribbled a few drops, but I could leisurely punch the paint out of the holes from the inside, with no water in the boat. The narrow neck of the seacock probably prevented me from reaching the full diameter of the strainer, but I was able to do enough that I had full water flow for the rest of the season.

You could probably do the same thing just using a rag to seal around the rod. A little more water would enter the boat, but not enough to worry about.

I hope you can save that last week on the water.

Michael

[Jim Lewis]

There is always the chance that some type of clam may be attached inside the intake system and when it opens can cause
reduced water flow....visual check of the water flow is always a good start along with actual engine and exhaust temps.....I was lucky with my recent temp gauge problem, it was a little corrosion at the point where wire attaches to sending unit.....cleaned it and everything worked normal.....good luck Jim

[sharkbait]

I had a similar problem where a barnacle got through the outside grill of the thru-hull and then grew inside. Being at a dock rather than a mooring I adapted a garden hose to the inlet line and back flushed the line after crushing the barnacle with a screwdriver.

[Joe Myerson]

These are all great suggestions, and all are in line with my own theories.

As I go over my notes from last year's season, I realize that I had a few brief incidents of the cooling-water alarm sounding late in the season. In that case it was barnacles restricting the inflow of cooling water, even though there was antifouling on the strainer, and the holes were opened with an ice pick.

I used the ice pick again this year, at the beginning of the season.

Well, if I can get the boat over to the yard in the near future, I'll find out for sure.

In some past seasons, I've been able to sail into November, but this year looks very unlikely. Where is that global warming when you want it?

--Joe

[RC James]

Perhaps a few more quick fixes:

1. Unclamp the saltwater intake hose from the water pump, and place a funnel into same hose, then open seacock and very care-fully pour MaryKate's On/Off Hull Cleaner into the funnel. Acid will work, also. This should clean any living items off the water intake, and will also clean the inside of the intake hose.

2. Remove the small water hoses from the front of the engine, and use a small dental tool to probe into the depths of the cooling system pipe inlets. Do not be surprised if you find a few obstructions that some judiciious probing will break through, and that a small river of rusting water and particulae will coat your hands and engine.

3. Still haven't been able to force myself to run a muriatic acid solution through the cooling system. Something about acid and iron and aluminum in contact with each other makes my blood run cold, and I'm not ready to invest in that 2GM20 yet.

[Joe Myerson]

Sounds like a good way to clear out the raw-water intake and cooling pipes.

[Joe Myerson]

I always like to update the board when I post a question, so here goes:

Creme Brulee was hauled last week and the diagnosis for the "cooling water temp." alarm is in. It was a faulty temperature sensor switch (did I get the terminology right?).

Anyway, all seems well.

--Joe