Colored clouds in water behind boat.

[Meast]

Hi!
Mercruiser 7.4 Bravo 3. Closed cooling. Problem is it leaves colored cloud in water. I have only been driving it for aprox 1nm after winter.
Starts fine, runs smooth. Pic taken at docks on idle.

 

[rick3452]

Loosing Coolant due to bad Heat Exchanger??? Did you check coolant level?

 

[Meast]

Thanks for reply.

Same thoughts crossed my mind after i posted. I have been loosing coolant last year. The coolant lost its color. I was thinking raw water got pushed into closed system, just enough keep gauge and engine at right temp.

 

[Bt Doctur]

Heat exchanger failure

 

[Meast]

Okay, removal for pressure testing and inspection and maybe possible fixing it.

 

[Meast]

Okay, engine drained. HE removed. Don't be shocked, but this is how it always been since i bought the boat 3 years ago. I was told it was nothing to be alarmed about but i have always cleaned system every winterization with new coolant liquid. All oils look good and keep levels. I have never noticed any bubbles from HE when lid removed.

What do you think?

 

[fhhuber]

First pic kind of looks like kicking up sediment...

Is that in water deep enough to prevent that?

Second pic... that stuff is just wrong.

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Should be able to pressure test the engine side of the cooling system similar to how you pressure test a car radiator. See if it holds pressure. If not, then find the leak (which will be the heat exchanger due to the symptoms described)

 

[Meast]

Depth is enough i think, aprox 7-9ft. Had that in mind as well but it wasn't that easy. Yea, coolant looks wrong. I will pressure test HE.

 

[Meast]

The heat exchanger was tested. No leaks. Now i dont know what...