2010 mercruser 5.7

[jwkoehn]

overheated motor , took care of problem i now have water gushing out of of a Y fitting on side of block this fitting also has the anti knock fitting attached what do I need to solve this

 

[Fun Times]

Would you be able to provide the engine serial number and a photo of the part/area in need in case it's something a bit different than what we can only speculate on with the info given thus far.

You may be missing or have a broken blue engine drain plug + O-Ring which should be item number 31, 32 as 29 and 30 is a knock sensor and Y (Dual) fitting.

Your serial number helps narrow down your correct parts guide as the following parts link is only a reference guess for you to start off with at this time, https://www.mercruiserparts.com/bam/subassembly/31876/12834/40

With the overheating that happen, let's hope there isn't too much other damage you may not have noticed just yet.
How long do you believe the engine overheated for?

 

[Scott Danforth]

if you overheated the motor enough to melt the blue plastic plug or the o-ring, that means the side of the block was well over 250 degrees. this would fall under the category of severe overheat

that also means that all your rubber exhaust bits long ago got burned up in your overheat.

i would be doing the following:

• compression test
• inspect the spark plugs for bits of aluminum on the electrods
• inspecting the exhaust hoses and flappers

 

[jwkoehn]

blue drain plug melted or broke off pulled both flappers they looked good but replaced anyway did not run long as it was 1st time out this year and I was watching gauges closely