No water coming out the block drain plug

[DevonDutka]

When winterizing my boat the last 2 years, when pulling the drain plugs, there is no water that comes out the port side engine block plug. The blue plug, even though it’s plastic, is hard to get out and very rusty looking. Why would there be no water coming out this plug, but the other 3 drain plugs?
I was replacing a large coolant hose on the starboard side of thermostat because of a deep groove from rubbing on a bracket and when I pulled it off I noticed the spring was all rusted into small pieces, so glad I decided to change that coolant hose. Could a piece(s) from that spring be blocking the port side engine coolant passages? I get good water coming out exhaust ports on the back of the boat.
This is a 99 MerCruiser 5.0L

 

[GA_Boater]

Welcome aboard, finally? :smile:

Two years ago you should have poked the drain to loosen the rusty build up. And last year too, but you can do it this year.

The drains are in the lowest section of the water jacket and sand, rust, mermaid scales, etc. all collect there. Use a screwdriver or what you have to poke through the crud.

 

[Scott Danforth]

You may have so much sediment that you may need to probe, flush with muffs, repeat.....