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Pipe connecting coolant system to exauhst?


WomanOnWater

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Hi all,

 

Not sure if this is the right section, but hoping someone can shed some light.

 

i have a Diesel engine, with what looks like a fabricated pipe going from the coolant system to the exhaust. I can’t think why that would be? Any ideas?

 

there is also a heat exchanger on the exauhst - not sure if that’s helpful context!

 

every time the engine runs, the bilge fills with water - I thought water was coming through the through hole fitting, but maybe it’s actually coming from the cooling system?

 

any ideas why you would connect these things?

A705DD9A-8D40-4642-81C8-A530A3D8986E.jpeg

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You have what is known as a wet exhaust system and looking at the size of your coolant pipes there is a heat exchanger inside the blue box (exhaust manifold) that pipe is connected to.

 

At the front of the engine you have two water pumps, a brass one and another one in a probably blue body that is driven by the alternator belt. The blue one pumps antifreeze and water coolant into the engine, then around the pipes in the heat exchanger to cool it and then back into the engine.

 

The other pump may also be belt driven or bolted straight onto the engine. This one has a brass body and a rubber impeller inside it. This pump sucks water out of whatever you are floating in and blows it through the pipes in the heat exchanger and then into the exhaust to silence and cool the exhaust hose. The rubber impellers need regular inspection, at least every spring, and the raw water system the brass pump bit) needs attention to stop it freezing and damaging stuff during the winter.

 

More explanations here http://www.tb-training.co.uk/15cool.htm#bmn55

 

You are free to print out whatever you want from that website for your own use.

Edited by Tony Brooks
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Looks to me like a wet exhaust - popular on river boats, but canal users (mostly) treat it with scorn.

I guess there's a pipe missing / damaged. It should run from the bottom of the pipe in the photo to a fitting in the side of the boat where the cooling water ad the exhaust fumes go overboard.

 

I se that nice Mr. Brooks has got there first...

 If the bilge is filling with water - and I guess the engine bay is filling with smoke - that the discharge tube is missing or damaged. If the original setup was done properly, there should be a plastic box somewhere in the run of piping.

 

Have a look and come back...

 

Here's a link to various forms of water block

https://www.google.co.uk/search?q=wet+exhaust+water+block

 

Edited by OldGoat
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Is the water in the bilge or engine drip tray?  If the later I suspect that either water pump might be leaking but if you do not have to top up the engine coolant (cap on the blue box exhaust manifold) then I would suspect the brass pump. However there is a lot of rust staining on the top of the manifold indicating coolant is being expelled from the engine system. Do you fill it to the brim frequently. If so stop dong that and only fill to about 1" below the filler neck. Also make sure the rubber seal under the filler cap is in good order.

 

If the water is in the actual bilge make sure its nor just rain water getting in - especially if its   a cruiser or semi-trad stern. The raw (canal/river) water has to be drawn into the boat somewhere and often through a weed trap with a removable lid so you can clean any blockages. Find yours and make sure the lid is not leaking.

 

In the photo no signs of an exhaust leak but I have known rubber exhaust hoses burn through and fill the bilge so have a good look at the exhaust hose.

 

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To bump this up today.

 

Judging by the staining on top of the manifold/heat exchanger there is a strong possibility that the engine cooling water - not the raw water - has no or insufficient antifreeze in it. Not a situation that is ideal at this time of year.

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