A couple weeks ago, I had the temp alarm go off on my 88 Hunter 28.5 with a 2GM20F. Found the antifreeze was low so I filled it up. I've been checking it and it keeps going down. (This is my second year with the boat.)
So, today I went up to the marina armed with a cooling system pressure tester and found that the system won't hold any pressure. I filled the anti-freeze up to the top of the neck and put on the pressure tester and the level of antifreeze goes down as I pump the tester handle. :-( I checked below the engine and there is no antifreeze that is collecting, and when running the engine, there are no bubbles or change in the level of the fluid as I watched it. I don't think it's a head gasket issue.
It seems to me that the antifreeze must be leaking out the heat exchanger into the exhaust, apparently out the back as there is no antifreeze that comes down the front inlet hose (raw water input). I was trying to study the installation and figure out how it is put together, to have a better idea of what I have to do to fix it. (I'm a fairly good mechanic, been rebuilding cars and even an Evinrude outboard V6 once!).
I'd like some coaching if there is someone that has been into this before, I'd really appreciate some advice. I found the coolant drain on the starboard side of the engine, mostly comes out brown!. I also found the lines that go back to the water heater (currently empty, I don't use it). What was in the water heater is clean water, no antifreeze.
Question 1: There is also two 5/8" lines that go from the heat exchanger outside of the engine compartment to some sort of white plastic vent valve, and back into the exhaust manifold mixer. What is this for??? (No apparent leak here either.)
Question 2: Will I need to pull the head to get the heat exchanger off? It doesn't look like it, but it is attached to the head. Also, will I be able to seal up the heat exchanger OFF THE ENGINE in order to find where it's leaking??? I'm not sure how to find the leak once I get it off.
Question 3: Will I need to remove the whole heat exchanger in order to fix it? Or can I remove an end?
I found a manual on line in another thread: https://sbo.sailboatowners.com/downloads/Hunter_gen_25628785.pdf
The boat get's pulled out of the water in about 2 or 3 weeks (our water will get this hard crust on it, way up here in the Minnesota!) I'll just keep refilling it until then. It doesn't go down too fast.
Mike
So, today I went up to the marina armed with a cooling system pressure tester and found that the system won't hold any pressure. I filled the anti-freeze up to the top of the neck and put on the pressure tester and the level of antifreeze goes down as I pump the tester handle. :-( I checked below the engine and there is no antifreeze that is collecting, and when running the engine, there are no bubbles or change in the level of the fluid as I watched it. I don't think it's a head gasket issue.
It seems to me that the antifreeze must be leaking out the heat exchanger into the exhaust, apparently out the back as there is no antifreeze that comes down the front inlet hose (raw water input). I was trying to study the installation and figure out how it is put together, to have a better idea of what I have to do to fix it. (I'm a fairly good mechanic, been rebuilding cars and even an Evinrude outboard V6 once!).
I'd like some coaching if there is someone that has been into this before, I'd really appreciate some advice. I found the coolant drain on the starboard side of the engine, mostly comes out brown!. I also found the lines that go back to the water heater (currently empty, I don't use it). What was in the water heater is clean water, no antifreeze.
Question 1: There is also two 5/8" lines that go from the heat exchanger outside of the engine compartment to some sort of white plastic vent valve, and back into the exhaust manifold mixer. What is this for??? (No apparent leak here either.)
Question 2: Will I need to pull the head to get the heat exchanger off? It doesn't look like it, but it is attached to the head. Also, will I be able to seal up the heat exchanger OFF THE ENGINE in order to find where it's leaking??? I'm not sure how to find the leak once I get it off.
Question 3: Will I need to remove the whole heat exchanger in order to fix it? Or can I remove an end?
I found a manual on line in another thread: https://sbo.sailboatowners.com/downloads/Hunter_gen_25628785.pdf
The boat get's pulled out of the water in about 2 or 3 weeks (our water will get this hard crust on it, way up here in the Minnesota!) I'll just keep refilling it until then. It doesn't go down too fast.
Mike