240 Sundancer coolant in engine bay

Craig Davis

New Member
Mar 18, 2023
2
Boat Info
1997 240 Sundancer
5.7LX V8 Alpha 1 Gen 2
Engines
5.7LX Alpha 1 Gen 2
Bought in 2018
Hello, 1997 Sundancer. It was overheating. I repaired the impeller and that works now. The coolant is still leaking somewhere into the engine bay. I’m guessing it broke a hose before when impeller wasn’t working. Thermostat has been replaced also. Is there any common places to start checking? Thanks.
First Post, New to boating. Millwright/Machinist.
 
Welcome to CSR. Your best bet is to fill it up again and let it run, see if you can see the leak while it's happening.

That said, I've more than once had a cracked coolant reservoir and/or had that small hose pop off. Perhaps start there, see if you've got any leaking coolant right after you fill it. Then follow that hose and check the "other end" as well.
 
Craig, along the lines of what's written above and with your note of being "new to boating", I'm wondering the same thing about whether you have closed cooling or an open/fresh cooling system (google those). Can you better describe... or maybe just post a picture of your engine? That would help us help you. Having a closed system on that boat is, by far, a rarity - not to say it can't be - but that's why we're wondering.

What color is the fluid that keeps showing up?

The best way to find a leak, though, is to just start looking. Clean the engine REALLY well and it helps tremendously to find a leak. In the end, the leak could be anywhere.

By the way... ain't nothing wrong with being new to boating... it's a good thing to be "new" to! Besides, we were all new to boating at some point in our lives.
 
Thanks for all the feedback. Here’s a photo of the engine. The impeller went on the Leg and the motor was overheating, and he kept adding antifreeze. Impeller is fixed and working now. I’m guessing a pressure leak from overheating occurred after the impeller failed.
 

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Thanks, Craig - that takes out the guesswork for us. Closed cooling and the green color indicates AF... unless someone keeps emptying their lime green Gatorade in your bilge :)

It's nice to see that the engine bay is pretty clean - that's a good sign of a well kept boat. Take a real close look at the engine - anywhere you have coolant lines - just trace them around - including the heat exchanger. You might get lucky and see telltale signs of coolant leakage.

If not, go ahead and spray it down with degreaser and water and clean things up real good. As noted above, check the overflow bottle and hose first. Then go ahead and borrow a pressure tester at Autozone - pump it up and then observe till you see the leak.
 
Closed cooling; who'da thunk? That's actually pretty cool!
Since you're basically dealing with a system fairly similar to an automotive cooling system, you can borrow-rent a pressure test kit and apply air pressure to the cooling tank (heat exchanger) and look for leaks without worrying about starting the engine.
 

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