Yanmar 3ym corrosion

[bouncingyellow]

Hi I need help , my 3ym has suffered servere corrosion on the aliminium block housing the centrifugal pump. Globs of yellow stuff also found inside choking the plumbing up, what had cause this? , I will appreciate any input.

[stevec195]

Is there no hint of a coolant leak? What plumbing in particular is exhibiting the yellow crud?

[bouncingyellow]

There was a slight coolant leak visible from outside around the pump on inspection, then prising the centrifugal pump away from the block in noticed the male end of the housing severely corroded, the yellow crystalline gunk was mostly around the thermostat and had blocked the hot water tank outlet.

[stevec195]

Uhmm, well it's difficult to say without tasting or seeing. But do you suppose your coolant was contaminated with sea water in addition to the leak at the pump?

[bouncingyellow]

I gave it a little taste and no sign of salt ???? Think I am going to pull of the heat exchanger and have a look at that,, . If my anode has fallen off my shaft could that be the culprit ? .

[stevec195]

Shaft anode unlikely culprit. Check pencil zincs in water heater and engine. Ensure engine has good ground would be a good start.

[bouncingyellow]

Okay thanks Steve I will check those. Thanks again

[stevec195]

Also, please no tasting of fluids from your engine-that was meant to be tongue planted in cheek.

[Cheechako]

Could be inappropriate coolant. Some coolants came out and had additives that became lumps of gunk. Others attacked aluminum. maybe that's really old troublesome coolant?

[a64pilot]

Originally Posted by Cheechako

Could be inappropriate coolant. Some coolants came out and had additives that became lumps of gunk. Others attacked aluminum. maybe that's really old troublesome coolant?

Dexcool as a good example, although it's orange. I thought the same

[bouncingyellow]

Cheekato , I agree. I found out that the engine installers did not use the right coolant, the coolant they used only had a half life compared to the yanmar specs thus turning bad and becoming very corrosive on the aluminium parts. Some other Aluminium parts around the heat exchanger have suffered corrosion as well , especially the male ends where the rubber hoses attach, anybody know of a 3ym for wrecking lead them my way.


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