496 HO - Mercruiser with antifreeze in crankcase
#21
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Nothing wrong with 496HOs. I love mine and know plenty more who do.
The air pump system is NOT sufficient for winterizing, especially in a really cold climate. You MUST winterize it the old fashioned way by running antifreeze through the sea water side of the cooling system. The sea water side of the cooling system will absolutely hold pockets of water in it by only using the air pump to push out water. The air pump system is only good enough for marginal temps to extend your boating season.
The air pump system is NOT sufficient for winterizing, especially in a really cold climate. You MUST winterize it the old fashioned way by running antifreeze through the sea water side of the cooling system. The sea water side of the cooling system will absolutely hold pockets of water in it by only using the air pump to push out water. The air pump system is only good enough for marginal temps to extend your boating season.
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HOBoater:
Sounds like you may have just had a failure in the factory stock head gasket, but it could also be a crack in the head, so isolate which it is. Raylar has stock new takeoff iron heads in stock and we have our 496 Raylar/Cometic MLS stainless head gaskets in stock as well as any other 496 parts you might need. We can give you some tips on how to properly clean the coolant from your motor and make sure you have a clean, water free crankcase as well as methods for checking the seal up after you reassemble. Call Raylar toll free @ (866) 496-8181 M-F Pacific time if you need parts and assistance.
Best Regards,
Ray @ Raylar
Sounds like you may have just had a failure in the factory stock head gasket, but it could also be a crack in the head, so isolate which it is. Raylar has stock new takeoff iron heads in stock and we have our 496 Raylar/Cometic MLS stainless head gaskets in stock as well as any other 496 parts you might need. We can give you some tips on how to properly clean the coolant from your motor and make sure you have a clean, water free crankcase as well as methods for checking the seal up after you reassemble. Call Raylar toll free @ (866) 496-8181 M-F Pacific time if you need parts and assistance.
Best Regards,
Ray @ Raylar
Last edited by Raylar; 05-08-2009 at 12:19 AM.
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yikes, sounds like I have the same problem. Just added a bunch of anti freeze, ran it for a day and it's low again. Not a winter problem I don't think, I've put 100 hours on this thing this summer at least.
I'll have to keep an eye on it.
I'll have to keep an eye on it.
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Believe it or not on the Mercrusier 496's, the dipsticks only go into the oil fitting at the bottom of the pan and run up along the side out of the engine so we have seen 496's with 2 -3 quarts of dex-cool in the crankcase that would not even show up on the dipstick until it was way to late!!
If you've got coolant in the oil, do not run the engine, drain the oil, pressure test the coolant system and find the leak. If the block is cracked its already over for the internals.
If its just a minor or moderate leak, find the leaking head gasket or cracked head or oil cooler leak and fix it right away! and then you can flush the oil system with oil and dexron mix and change the filter and refill with fresh oil, run the engine lightly for a few hours and then re-change the oil and filter until no more oil contamination shows in the filter and cooler. If you are real lucky and you catch it in time and your oil pressure runs at normal ranges and your filter, cut open shows no metal debris you might just be damn lucky!! Hope you become Damn Lucky!
Best Regards,
Ray @ Raylar
If you've got coolant in the oil, do not run the engine, drain the oil, pressure test the coolant system and find the leak. If the block is cracked its already over for the internals.
If its just a minor or moderate leak, find the leaking head gasket or cracked head or oil cooler leak and fix it right away! and then you can flush the oil system with oil and dexron mix and change the filter and refill with fresh oil, run the engine lightly for a few hours and then re-change the oil and filter until no more oil contamination shows in the filter and cooler. If you are real lucky and you catch it in time and your oil pressure runs at normal ranges and your filter, cut open shows no metal debris you might just be damn lucky!! Hope you become Damn Lucky!
Best Regards,
Ray @ Raylar
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Thanks for the responses, I have a couple questions. Does the 496 have alum heads? The oil gets dirty pretty fast, I've seen alum heads do this to oil.
Or, it could just mix real fast with the oil that doesn't get sucked out and looks kinda dirty sooner than normal.
Once I get the oil out, is there a way to check besides the baby puke method? Maybe it's not sucking it out, the antifreeze part.
I put about 1/3 of a gallon into the reservoir recently, and it is reading low again. Hope it's not too late, but at least its the end of the season.
Any advice on pressure checking the system?
Thanks-
Or, it could just mix real fast with the oil that doesn't get sucked out and looks kinda dirty sooner than normal.
Once I get the oil out, is there a way to check besides the baby puke method? Maybe it's not sucking it out, the antifreeze part.
I put about 1/3 of a gallon into the reservoir recently, and it is reading low again. Hope it's not too late, but at least its the end of the season.
Any advice on pressure checking the system?
Thanks-
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Don't bash the 496 engine! Improper winteriztion will do in any marine engine. Get the Merc manual and follow the winterization instructions exactly and completely and you should not have any block or head cracking problems. Do it wrong or have somebody else do it wrong and you will have a disaster in spring just like anyother marine engine!
We have also heard of some shops using 50/50 water and Dex-Cool mix when refilling 496's that will be in winter freezes. THIS IS WRONG, THEY MUST BE FILLED WITH 100% DEX-COOL, every 496 owner-log this in your memory chip and make sure your servicer knows this also!!
Best Regards,
Ray @ Raylar
We have also heard of some shops using 50/50 water and Dex-Cool mix when refilling 496's that will be in winter freezes. THIS IS WRONG, THEY MUST BE FILLED WITH 100% DEX-COOL, every 496 owner-log this in your memory chip and make sure your servicer knows this also!!
Best Regards,
Ray @ Raylar