See full version: Water leak behind in bellhousing Mercruiser 120
The whole back of the block had rust all over it. I hit it with a wire wheel on a drill for a better inspection. But I will look there too. The front core plug is partially pushed out and has rust trails coming from it but it was not leaking in the water or on muffs. [links]
Stupid question but doesn't the expelled water from the engine go through the exhaust? My plan was to make a block off plate on the manifold (almost where it goes into the rubber boot) and then pressurized the system. [links]
The water was leaking in when I was the running the engine on muffs and when I went to the lake a couple weeks ago. I'm not sure where to go from here. here
I bought an '84 Bluewater with a 2.5 Mercruiser and Alpha 1 outdrive last year. Used it all last summer and winterized. Must not have done the best job because it is leaking water behind the bellhousing and down into the flywheel. I understand I may be an idiot for not properly winterizing and I accept that.
Today I decided to tackle this issue. I removed the stern drive and pulled the engine. Removed the flywheel and I can't see anything wrong. Both "freeze" (not what they actually are meant for) plugs are still there and I don't see any cracks in the block.
Look for white smoke that looks like steam and lasts a minute or more after start-up. Steam will not linger on the surface of the water, but rise up very quickly. Steam in the exhaust indicates that water has entered the combustion cylinders.
Look at the condition of the exhaust smoke while the engine runs. Bluish colored exhaust that disappears after 30 seconds of warm-up is normal. Some amount of oil burning during start-up will occur and leave a low-lying cloud of smoke over the water. more
Turn the engine over several times without ignition. If the starter seems to spin fast for a second, then catches and spins fast again, it could be the signs of hydrostatic lock. Water that has entered the cylinders will not compress and stop the combustion cycle. If the engine does not start or turn over at all, it could be a complete hydrostatic lockup. [links]
Outboard marine engines work much hard than automobile engines. They do not have a feature that allows them to coast after a surge of power and momentum, like cars or trucks. For this reason, outboard engines wear out faster, absorb more heat over a longer period and work under a constant load. Outboard engine cylinders also take a beating when it comes to ingesting water from their environment or cracking as a result of improper winterizing procedure. Some outboard cylinders simply crack from heat and stress. more
Observe the starting sequence of your engine on your next outing. Upon starting the engine, note whether the engine lugs during starting, or seems to pound or hesitate before the engine starts. Stop the engine. Unclasp the top engine cowl case. Use a socket and wrench to remove the spark plug, or multiple spark plug wires from the tops of the spark plugs. Use a piece of coat hanger wire to ground the ends of the plug connectors to the engine block. here
Mercurys MerCruiser gas engines give you speed during launch and as you sail across the open seas, lakes, or rivers. Inboards work differently from outboard options, so it is important to understand how they function before you purchase a new inboard gas engine on eBay.
How do these engines work? more
Mercurys MerCruiser inboard engines install inside the hull of your craft. The motor typically connects to the drive shaft, which transfers power and steering directions to the exterior of the craft. This protects them from the elements and offers a number of other benefits, including: [links]
Also, it pays to test the pressure cap on your cooling system every three or four years. They do eventually wear out. Most automotive shops have an appropriate pressure tester they can check this with, and it only takes a minute to perform the test. Or you can just replace the cap as part of your preventive maintenance The pressure rating is typically embossed on the cap.
Besides keeping the “plaque” buildup out of the raw-water side of your cooling system, you should of course test your engine coolant to make sure it’s at an adequate protection level temperature-wise. Inexpensive antifreeze hydrometers to verify this are available at just about any automotive parts store. [links]
Think of the heat exchanger on your boat engine as the radiator on your car: They play the same role in shedding heat away from the closed side of the system.
No matter how sophisticated your raw-water strainer is, understand that it was only designed to keep weed and other relatively large debris from entering your cooling system and clogging the raw-water pump. Things like micro-organisms, calcium, and lime are still getting by the strainer and are indeed going to leave deposits inside the raw/seawater side of your cooling system. Left unattended, this stuff will eventually form a coating inside the comparatively small passages inside your heat exchanger. Think of it as cholesterol plaque in your cooling system. here
The trick with any engine is to get it running as hot as it can run without causing any damage. That’s when you know it’s running at peak efficiency, assuming proper fuel and exhaust system design. Consider a modern automobile that will typically run at 215° F. It is undoubtedly getting much better mileage than its 15-year-old counterpart.
In the old days, many marine engine cooling systems were of the “raw-water” variety, meaning simply that they relied on pumping whatever water the boat was floating in through the engine and pumping it out the exhaust system—salt water, polluted water, algae-infested water, whatever was available. The impact this had on the longevity of the engines was profound, especially in the extra-corrosive saltwater world.