Exhaust manifold discovery?

[TXGlastron]

Good morning. With all the things I have learned about this boat I purchased, GXL 235 Mercruiser 5.0, I think I just found a serious issue. Hopefully I’m attaching a picture as well. Is this my exhaust manifold cracked?

 

[Lou C]

ahhh, wellll...YEAH
Was this boat winterized? If so, how?
if that's cracked check the other manifold and the sides of the block on both sides, as well as checking for water in the oil after firing it up.

 

[airshot]

That is a pretty serious crack, hate to see what the rest of the block looks like !! Quite noticible...you didn't see this before purchase ??

 

[TXGlastron]

I don’t see any other issues on the block, and the motor runs well. However, I’m thinking this is not safe at all to use and must replace. Am I correct?

 

[Lou C]

of course!
that will fill your bilge with water in no time!
how long have you owned this, & has it been run yet?

 

[Scott Danforth]

That is a classic example of thermal declination material breach due to volumetric expansion

Your block is most likely cracked too

If your block isnt, buy a lottery ticket

 

[TXGlastron]

After I posted that picture, I discovered both exhaust manifolds cracked. It was NOT winterized properly and the cracking was a direct result. I wound up putting in a Quicksilver rebuild motor.

 

[airshot]

This is why I do my own work, way to many shops charging big bucks for poor service !

 

[TXGlastron]

Airshot, I’ll take my lumps as deserved. The winterizing was my fault. I had my boat on the lift, and hadn’t been able to get back to it for a couple months (it’s several hours away from me). The lake level had gone way down back in 2021, and it got stuck on the lift. This is where I’ll take my lumps. I could have easily pulled the drain plugs, but I forgot to do this. Huge lesson learned! Even in TX, winters are cold enough to ruin boats.