Yanmar IGM10 white smoke and seacock filled with duck weed

[conks01]

Hi,

A couple of weeks ago I went out on my Westerly Pageant in the Bristol Channel for a couple of hours and then headed back to the mooring in the river (Brue).

Midway down river, I noticed white smoke coming out of the rear, thankfully I was near to the mooring and managed to get onto it.

I then checked for water flow from the rear and noticed there was literally nothing coming out.

Having inspected the engine seacock, I found that it was full of duckweed. It was extremely difficult to remove and I was forced to cut off a painters pot wire handle and use it to force down the seacock and free up the duck weed. This worked and the water then flowed freely from the seacock

Thinking this would solve the problem I started the engine. Unfortunately, there was still no water coming out of the rear however.

I suspect the duck weed has found its way into the engine, blocking it.

For the record, I have removed all hoses and checked them, which were clear. I've also changed the impeller in case the former had become worn from having no water pass through it, again this didn't solve the issue.

There is water passing from the water pump to the hoses above, I checked that.

My old crew mater believes that we need to remove the head, to unblock the water jacket/channels? I'm no expert whatsoever and this sounds dramatic to me.

I was wondering what options or alternatives there may be. Does anyone have any advice please.

Many thanks.

 

[[70521]]

Have you tried blowing down the pipe that enters the engine block? Was there any resistance?

 

[vyv_cox]

No water at all exiting the engine suggests that none is reaching it. There is a diverter by which water either goes into the engine or to the bypass. Sounds like a blockage there.

 

[Dellquay13]

No water at all exiting the engine suggests that none is reaching it. There is a diverter by which water either goes into the engine or to the bypass. Sounds like a blockage there.

I think on the 1gm10 there is an external T piece on the front after the pump for the diverter. One outlet leads into the block for cooling and the other is the bypass hose to the thermostat on the block cooling exit. Duck weed could have bunged up either that diverter or the thermostat.

 

[VicS]

This diagram, from the workshop manual , shows the cooling water system and flow paths.

( the sub-diagram that shows the flow path is however rather misleading in that it appears to show two inlets to the mixing elbow when, in fact, they are combined into just one hose from the thermostat cover to the elbow. )

 

[Birdseye]

Steam or white smoke? If steam then clean out the cooling system. If white smoke ie with a film of oil on the water behind the boat, then likely its a cylinder head off job. Not that difficult on the little Yanmar - been there , got the T shirt. In my case it was a failure of the water injection into the exhaust which in turn had cause hot sea water to get into the cylinder head and corroded through a part of the casting.

 

[conks01]

Thanks all for your guidance. I'll have a play to see what can be done. It's white smoke bellowing out and not steam.