Water in the Antifreez

[CarpeDiem40]

HI,

I have a volvo penta D2-55C (2006)

Since last summer I noticed an accumulation of antifreeze in my engine pan. Antifreeze comes from my overflow hose installed on my antifreeze cap (I do not have a expansion tank).

In my mind the water could only come from my hot water tank, so I changed it. Which did not solve the problem.

I still have a surplus of antifreeze, although obviously I never add. My engine is sometimes very very hot, but the alarm never bip and the water comes out normally by the exhaust.

There is water that mixes with my antifreeze, but I have no idea where this water comes from.

Last week, I checked my heat exchanger. To my surprise there was an impressive accumulation of rubber from old impellers. the entrance to the heat exchanger was completely blocked (see the pictures).

My question :
How is it that if the hole was completely plugged, that the water was coming out normally by the exhaust.
From where can come the water that mixes with my antifreeze.

Thanks

Pierre

 

[Scott Danforth]

start by doing the maintenance in your system. at a minimum, you need to clean all the debris from your heat exchanger (you should be checking that every year)

your heat exchanger would be the first place where raw water could mix with your coolant. you could have a breach.

if you boat in salt water, you will want to find the issue and correct it quickly

 

[jerryjerry05]

That's a LOT of rubber!!
I'm surprised you didn't over heat?
Then again maybe something got hot enough to push anti-freeze into the pan?
From the amount of chunks, I'd inspect the inside of the pump for sharp edges,
inspect the cam in the pump?
Since you have a closed system? do a pressure test.
The impeller should be changed at the least every 2 years.
If you boat a lot?? change it yearly.