Our 1987 Mark I lost all of the coolant into the bilge on our way out for a sail. We sailed back to the slip (that's a story for another day). I'm currently in the process of tracking down the leak. I checked the obvious: hoses and clamps.
I can put water in the tank and run the engine until it comes up to normal temperature, about 160- 175 degrees. Run for 10-15 minutes in gear. After I shut it down and check the coolant level, it is down just a little. Over time (about 1-2 hours) it all drains out of the tank (Tank = Radiator cap tank) and into the bilge.
The other thing that is puzzling is that the water heater is not heating the water.
Here are some facts and plan of action:
. Engine will run for 45-60 minutes at normal temperature and not lose coolant
. Does not heat the water in the water heater
. Over time the coolant drains into the bilge
. There is not any water in the oil
. I replaced the oil pan last fall and this required the engine to be be disconnected and lifted up, so all of the hoses were disconnected and reconnected.
I will check the hoses and clamps again
I will pull the heat exchanger to check for internal leaks and cracks
I will look at the connections to the water heater. (I will first make sure the heater is working on shore power)
My questions are:
. Are there any other pieces I should test?
.Why is the water not getting hot in the heater?
TIA,
.
Ralph
Still a Thrill # 765
WK, STD Rig
Lake Texoma, TX
You will probably get a lot of suggestions. Assume you have the M25 engine and not a MKII? You may have an antifreeze shut off valve that prevents circulation of antifreeze through the hot water heater. I think Catalina typically installed this valve on boats in the 80's. If that was closed, then the water heater would certainly not warm up with the engine running. I don't know where it would be mounted on the C36. It was in the engine compartment under the sink on our 1986 C-30 with an M25..
Dry engine pan area and observe where the antifreeze is dripping from. If you are loosing that much, it would be pooling near the leak source. If that doesn't reveal it, pad each hose connection with a paper towel. You should not see any evidence of moisture. I had a leak and it turned out to be a metal bur on a heat exchanger nipple- the clamp was tight but the hose would not seal because of the bur. If the hoses are original, they are getting up there in age and may be loosing the ability to seal.
Good luck
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
My Mk1.5 does not have a coolant recovery bottle, and yours may be the same way. Some engines (mine is the M35AC) apparently did not come with the little plastic reservoir for the coolant to overflow into. If your engine is like mine, then follow that hose from the top of the "radiator cap" and I think you might find that it just drains into the engine sump. So if the coolant is full, after you run the engine for an hour or so, the coolant heats up and will overflow into the engine sump. I am in the process of shopping reservoirs to install to remedy this. Search on the forum for a recent discussion on coolant reservoir bottles and you should find it. As for the water heater, my guess (like the previous respondent) is that you either have a valve somewhere that is closed, or a hose is disconnected. The only such valve that I have is right on the back of the water heater, at least that's the only one I have located.
Don Lincoln
"Nancy Lynn"
1993 Catalina MK1.5, Hull 1238
LaSalle, MI (Lake Erie)
Universal M-35AC
When installing a new coolant recovery tank, what is the required height of the tank in relation to the radiator cap. I have a 1985 C36 with a model 25 diesel and am trying to figure out where I need to install the new recovery tank. Does the recovery tank need to be below or above the radiator cap to work effectively? I am thinking about buying the Westerkbeke recovery tank but noy seeing any installation instructions.
The recovery tank needs to be above the radiator cap.
Tim Askew
S/V Allure
1990 Catalina 36 Hull # 1079
Std Rig, Wing Keel, M25XP
3 Blade Auto Prop
Elizabeth City, NC
I did some more trouble shooting and found 2 things:
1. The vented loop coming off the heat exchanger had a small leak in the fitting. I changed the duckbill and I was still getting a small dribble of water. I'm going to change the fitting. Does anyone know the size of the vented loop on a 1987 Mark I? I believe it's 5/8, but it could be 3/4. I'm also going to replace the hoses that go to it from the heat exchanger.
2. As I was looking for leaks on the back side of the engine, I noticed that the aqua muffler was vibrating. See photo. The top half 'A' was some what stationary, but the bottom part 'B' was vibrating very fast. I'm assuming that it should not be doing that. Is it just the rusted screw that has failed or do you thing the muffler is starting to fail?
I also noticed that it was heating the water heater. I removed the cutoff valves to the heater when I replaced it years ago.
I could see water in the tank when I removed the radiator cap, so I did not lose a significant about of water when it sat for a week.
TIA,
Ralph
Still a Thrill # 765
WK, STD Rig
Lake Texoma, TX
How is the muffler attached to the boat hull? On older Catalina's the "lower half" is typically a wooden or fiberglass bed that the muffler screws into. The bed is bonded (fiberglassed or glued) to the hull. (On the MKII, the hull liner has the bed molded into it.) From what you describe, it seems that your muffler bed is seperated from both the hull the muffler.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
[quote=StillaThrill]
1. The vented loop coming off the heat exchanger had a small leak in the fitting. ...
2. As I was looking for leaks on the back side of the engine, I noticed that the aqua muffler was vibrating.
[/quote]
Neither of these things would affect the coolant levels, of course, since they both involve raw water discharge.
I've had to reglass the muffler in our '85 onto the hull a couple of times, but not since I switched to a hump-hose connection from the exhaust header (cut down the vibrations).
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
If it's losing all the coolant, you might consider getting a pressure tester from the local auto parts store (most of the "chain" places have them available in their loaner tool program). It makes it much easier than running the engine until the coolant loop gets up to pressure and temperature to look for leaks. Considerably safer (and more comfortable) than trying to look over a hot engine with moving parts.
Dan & Amanda Reed
1989 Catalina 36 #947 Miss America
Fin Keel Std Rig
FL Panhandle
I'm sure the muffler is not attached to the hull based on the way it was vibrating and that screw looks like it has rusted thru. So I will look at the muffler as a separate issue. I will check the pressure. Thanks for the suggestions.
Ralph
Still a Thrill # 765
WK, STD Rig
Lake Texoma, TX