2001 Volvo Penta 5.0 GL cracked block

Laneman25

Petty Officer 3rd Class
Joined
Oct 24, 2023
Messages
75
Wish I wasn't posting this but it happened. I would say that I carefully drain it each winter but obviously I didn't do something right. I have fond memories with the family on this boat. I always drain the two plastic plugs under the risers, both block drains, and the water pump. I also run a zip tie in and out of the drains to make sure all water comes out. The crack is T shaped just below the dipstick tube where yo see the water stains. Any chance of a JB weld or something, or is it toast?
 

Attachments

  • block.jpg
    block.jpg
    971.9 KB · Views: 9

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
29,118
Gee, sorry that happened. Water is tricky and can get trapped in areas of the block. I always filled my block with straight automotive antifreeze for winter, since I was always uneasy about water hiding somewhere.

The good news is that rebuilt blocks are plentiful and relatively cheap. On MerCruisers, blocks are pretty easy to replace, once you get the hoist figured out. Hopefully V-P is the same.
 

Laneman25

Petty Officer 3rd Class
Joined
Oct 24, 2023
Messages
75
Well I've watched a few videos and several boat owners had long term success with JB weld. If anyone here has tried it please add some tips.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
14,303
You also have to pull off the bottom of the big hose between the 'stat housing and the front circulating pump, did you do that?
GM cast iron blocks were never meant to be open cooled due to how cast iron rusts. So many rust flakes it is easy for passages to get clogged with rust flakes or even just sediment etc. from shallow water. I have a set of picks that I use to rod out the block drains each time I winterize it. When/if I repower my boat it is getting a half closed system for the block. Much better, easier to winterize and longer engine life.
One thing I noticed is this, it really helps to fill the block with the correct PG antifreeze for winter, because I have found that I rarely if ever have to poke one of the drains to get it to drain fully. It reduces corrosion when the boat is in storage, that's my opinion. And unlike many here, my use is 100% salt water. Block is original, heads were replaced 9 years ago (past overheat damage).
 

Laneman25

Petty Officer 3rd Class
Joined
Oct 24, 2023
Messages
75
You also have to pull off the bottom of the big hose between the 'stat housing and the front circulating pump, did you do that?
GM cast iron blocks were never meant to be open cooled due to how cast iron rusts. So many rust flakes it is easy for passages to get clogged with rust flakes or even just sediment etc. from shallow water. I have a set of picks that I use to rod out the block drains each time I winterize it. When/if I repower my boat it is getting a half closed system for the block. Much better, easier to winterize and longer engine life.
One thing I noticed is this, it really helps to fill the block with the correct PG antifreeze for winter, because I have found that I rarely if ever have to poke one of the drains to get it to drain fully. It reduces corrosion when the boat is in storage, that's my opinion. And unlike many here, my use is 100% salt water. Block is original, heads were replaced 9 years ago (past overheat damage).
Yes, pulled the big hoses from water pump
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
14,303
So then I’d guess there was some sediment in the bottom of the block passages that prevented all the water from draining.
 
Top