Join Date: Oct 2007
Thanked 3 Times in 3 Posts
Rep Power: 8
Hole in block!
I have a raw water (salt) cooled Yanmar 2GM that runs like a top. The other day I noticed some white powder forming on the top of the block. I then noticed steam coming out from this same area while the motor was running. It turns out there is a pin hole, in the block where the valve cover meets the block. I have a mechanic scheduled to take a look at it, However, I have to believe the diesel is toast.
How can the corrosion be so severe that it has eaten through the block, and yet, the engine runs great? It starts perfectly, has plenty of power, and has no symptoms of any problem (except for the steam, and salt!). This absolutely amazes me!
Why has the corrosion advanced to this point, though the internal motor zincs never seem to be attacked?