Buy/rent a coolant pressure tester. They attach to the radiator where the cap screws on.
Do you have a water heater that is heated by the engine? I do and my fittings weep a small amount. Check for leaks in the engine heat exchanger tubes and heads. Disconnect the inlet and outlet seawater hoses. Plug the outlet securely. Pressurize the inlet with air. Check for bubbles in the glycol by removing the radiator cap. Be careful not to use too much pressure. 5 to 10 psi would probably be sufficient. You can disassemble the seawater to freshwater heat exchanger and check for holes. I would guess that this is the most likely cause. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Sun, Oct 7, 2018, 4:28 PM bwhitmore via CnC-List <cnc-list@cnc-list.com> wrote: > Hello all, > > 1 have a 1994 C&C 37/40+ with a Yanmar 3JH2E engine. When I changed the > coolant last year, it seemed like about 12 oz less coolant went back in. > Since then. I've noticed the overflow tank seems to be dropping a little, > and I've topped it off 3 or 4 times. In total, I've probably added 16 to > 32 ounces of coolant. The exhaust exits the boat downward, so I don't > get a good view of the existing exhaust, but I'm not seeing evidence of > steam as I would expect if I had a head gasket leak. The oil looks fine. > There's no evidence of oil in the coolant. There's no evidence of coolant > leaking externally ( ie orange in the engine bilge). We get the boat off > the dock 4 to 6 times a month, each time motoring about an hour per trip > (30 minutes out, and 30 minutes back in after sailing. I've only owned the > boat about 18 months, so there could have been a preexisting condition. > > Any ideas, and is there a way to figure out what is going on? Should I be > worried? > > Thanks! > > Bruce Whitmore > > Sent from my Verizon, Samsung Galaxy smartphone > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > >
_______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
