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.

 

[airshot]

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.

Most of us boat owners have had to learn some hard lessons over the years, your not alone !

 

[Yegboats]

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.

live and learn,working at a dealership I see a few every spring. Thanks for the update.

 

[Lou C]

Low maintenance boat = outboard
Raw water cooled I/O = unforgiving of even 1 mistake
Closed cooled I/O is better but there'd still be damage
I love Chevy small blocks but at 70 years old doing this over 20 years there's no way I'd have another raw water cooled I/O here. They are just an enormous pain in the rear.

 

[Mc Tool]

Low maintenance boat = outboard
Raw water cooled I/O = unforgiving of even 1 mistake
Closed cooled I/O is better but there'd still be damage
I love Chevy small blocks but at 70 years old doing this over 20 years there's no way I'd have another raw water cooled I/O here. They are just an enormous pain in the rear.

Yeah , Ive always been at a loss as to why anyone wouldnt run proper coolant thru a heat exchanger . I wouldnt put salt water in my car ,even if I drained it after every use. If I could figure a way I would run a heat exchanger on my outboard ,and I schedule lake trips to give the outboard a few hours of freshwater flushing ......we do fish at the same time

 

[Lou C]

I have seen guys who are commercial fishermen out in my harbor with their boats....some are left out all winter, this year it was in the ice, etc, and they come out with a fresh battery, fire up the outboard and motor on. None of the nonsense that I/O owners have to go through trying to make a car engine live in a boat!

 

[jlh3rd]

fwiw. The 2 years in the brackish upper chesapeake with my new in 2021 Merc 115 has not hurt it. Just changed the impeller and checked the thermostat. No signs of corrosion. It does get a fresh water 2day lake run every summer, guess that helps.

 

[airshot]

Having an outboard that self drains helps a lot in salt water. Glad I am not close enough to salt water to have those issues.

 

[Lou C]

It’s not salt water so much it’s the pain of getting at the drains on V6s & V8s, that’s what would stop me from buying another. You wait too long just one time and you’re done.