Anti-freeze missing..HELP !

[stunod]

Hello everyone,<br /><br />About every 3 trips out with my boat, (driving about 4-6 hours per trip)I notice about 8 oz of Anti freeze is Missing. I checked the oil and its still a beautiful golden color.<br /><br />Question: How can I check to see where the anti freeze is disappearing to? <br /><br />I looked around the engine, but its dry, no hose leaks. (I think)<br /><br />SPECS: water cooled/ 190 merc/ 470 engine /I/O<br /><br />Thanks in advance,<br />Lou

 

[Trent]

Re: Anti-freeze missing..HELP !

Head gasket or manafold.

 

[stunod]

Re: Anti-freeze missing..HELP !

Hi Again,<br /><br />If Head Gasket or Manafold, Is it dangerous to drive it???

 

[Spidybot]

Re: Anti-freeze missing..HELP !

I think it's right. Your coolant runs in a closed circuit so if it disappears (and shows no leak inside the boat), it must be leaking into the combustion chambers (and be exhausted with the fumes). <br /><br />Coolant in the cylinders is not good. It affects combustion, oil film and may result in buildup.<br /><br />If coolant leaks into the manifold after the cylinders, it's blown out and makes no harm.<br /><br />Be careful not to run witn insufficient coolant. Overheating will add to your problems.<br /><br />Theoretically it could leak in the heat exchanger but in that case the level could as well stay normal while the collant eventually get replaced by sea water.<br /><br />Get a compression test first of all.

 

[Down South]

Re: Anti-freeze missing..HELP !

Hi Stunod,<br />I'm not sure you have a problem. Are you filling your cooling system to the top every time you notice it's not completely full. The cooling system has to have room for thermal expansion of the liquid coolant. When the coolant heats up a certain amount of it depending on the size of your cooling system will be forced out through the radiator relief (cap on the radiator or heat exchanger) On automobiles this relieved coolant is directed to a surge tank where when the engine is cooled back down the coolant is siphoned back to the radiator.<br /><br />Do you have a surge tank on your cooling system? If you do you can be loosing coolant through a leaking hose from the exchager or radiator to the tank.<br /><br />If you don't have a surge tank then expect to find the cooling system to be a 1/2" or more from the top. It's normal.

 

[stunod]

Re: Anti-freeze missing..HELP !

To REPLY to UU's Quotes:<br /><br />"Coolant in the cylinders is not good. It affects combustion, oil film and may result in buildup."<br /><br />Would it show up in the oil? When I checked the oil, it's a normal-golden color. How would I confirm "coolant in the cylinders"?<br /><br />TO REPLY TO DOWN SOUTH<br /><br />"Are you filling your cooling system to the top every time you notice it's not completely full."<br /><br />Yes, I fill it to the top and I do have a reserve tank that it's suppose to go to,but the tank is dry.<br /><br />"If coolant leaks into the manifold after the cylinders, it's blown out and makes no harm."<br /><br />The manifold is the original 1986 and the riser was changed 3-4 years ago. <br /><br />But wouldn't there be white smoke or unusual amounts of exaust if it did? I see nothing unusual with the exaust.

 

[Down South]

Re: Anti-freeze missing..HELP !

Stunod,<br />If you have a bad head gasket or cracked head compression from the engine will usually pressure up the cooling sys and force coolant out of the system. You would notice this quickly. Some leaks don't show up till the engine has cooled though. If any coolant that is getting into the cylinders it would be noticed when the engine is first cranked by a lot of white smoke coming from the exhaust.<br />I'm not a marine expert but I do work on industrial engines all the time and I'm not exactly sure how your cooling system is set up. You have an enclosed cooling system so somewhere there has to be a heat exchanger. Exchangers can be a culprit to. Especially the tube type. If the exchanger is leaking then you won't see the leak anywhere. The coolant will be going out with the raw water. <br />Just some ideas, Hope this helps.<br /><br />Good luck