Crack in heat riser

[Teardropty]

I have a new to me 1986 Seville. It has a Mercruiser 3.7 170 installed. The engine ran when I purchased it but it obviously needs some TLC. I know these engine have a bad history but I would rather try to address what I have than put something else in. Having said that when I pulled the exhaust off as part of pulling the whole engine I found a crack in the manifold INSIDE. I have attached a photo of it. The crack doesn't seem to extend to the outer part of the riser. My question is does this crack cause issues? Does it need to be repaired/replaced? Any thoughts are appreciated. Thanks in advance.

 

[dwna1a]

I would replace it and the manifolds. A fix would be a bandaid in my book

 

[Teardropty]

I would replace it and the manifolds. A fix would be a bandaid in my book

Hi and thanks for the reply. I made a mistake, the riser is fine, its the exhaust manifold that has a crack in what I would call the divider. Not sure if that makes a difference.

 

[Skybolt]

The issue with the center riser is that is common, can lead to water ingestion. That crack is usually caused by the riser gasket leaking and water dripping on the divider. Which also leads to the exhaust valves tuliping and sometimes deteriorated cylinder walls. You need to do a compression test and possibly pull the heads based on the findings.

The manifold and risers need to be replaced. Good luck.

 

[Teardropty]

The issue with the center riser is that is common, can lead to water ingestion. That crack is usually caused by the riser gasket leaking and water dripping on the divider. Which also leads to the exhaust valves tuliping and sometimes deteriorated cylinder walls. You need to do a compression test and possibly pull the heads based on the findings.

The manifold and risers need to be replaced. Good luck.

Ok, THANKS so much, that makes sense. Will do a compression test and go from there.