water leak from exhaust elbow exhaust hose connection

[KiwiBeanie]

Hi all

i removed the exhaust elbow for cleaning and when I refitted today when I ran the engine to check for leaks there was a trickle of water coming from the exhaust hose connection to the elbow. With the engine off i loosened the hose clamps and more water came out. Is this normal that water would come from this connection? it seems that if water is this high up the exhaust hose it is not far to the engine.

i have tightened the hose clamps and ran the engine with no leaks and plenty of water from the exhaust outlet. Other than remove the exhaust elbow i haven't done anything else so i am thinking this is normal as it must have been like this previously as nothing has changed except a higher water flow.

[Symphony]

No. There should not be water in the exhaust hose at that point if the engine is not running. when you stop the engine the seawater in the system drains down into the muffler/waterlock. It is designed this way so that water cannot go back up into the engine.

[KiwiBeanie]

next question then is why is water coming from the exhaust hose. there is plenty of water coming from exhaust outlet so doesn't seem to be a blockage.

[Yngmar]

Which engine? On our MD22 there is a low point in the injector hose that always has water sitting in it. In that case it would be normal.

[KiwiBeanie]

It is an MD22. But it was water leaking from the exhaust hose not the injector hose

[Yngmar]

Okay, so water should obviously not be leaking anywhere. If it does, check if the hosetail on the exhaust elbow is smooth enough and not corroded and tighten the hoseclamps sufficiently. If corroded, clean it up. If corroded through, the elbow needs replacing, although on the MD22 it's usually only the injector part that rots away with some regularity, and luckily that's available separately.

If the boat is moving (rolling), some of the water sitting in the injector hose and the heat exchanger can trickle down the wet exhaust, but that should be only a very small amount. Might be enough to make you think the whole exhaust system is brimful with water when it isn't though.

When the engine is off, there should not be water sitting this high up in the exhaust system. If it does, investigate why by following the exhaust system to the point where it leaves the boat. First thing to check is how high it sits in the exhaust muffler, to make sure there even is a problem at all (other than a small leak, which it sounds like you fixed already).

[KiwiBeanie]

Thanks for the reply. it was a trickle under high rpm and then when stopped i loosened the clamps and more trickled out. not gushing. tightened clamps and no more leaking, but will remove once more to see if there is water sitting in the hose. although from your reply i am thinking not.

I removed the elbow to clean, soaked in acid for a couple of days. The injector fitting disintegrated so replaced that otherwise elbow was in not too bad a shape. The elbow didn't look too bad before cleaning but increase in water flow is very noticeable.