Turbo Flange Leaking Exhaust from Heat Shield

[Richard Lynch]

Can you guys give me some tips on a repair? See pictures. I have been smelling exhaust and found evidence of Exhaust Leaks from around the Turbo Flange and I believe from both sides or maybe it is spilling all around the Heat Shield.

I am able to feel the exhaust air pushing out of both sides of the heat shield.

You can see Exhaust Dirt on the new Air Filter. This is after just a few hours of run time.

2007 QSM 11 670

Topic

[Tony Athens]

Dry QSM11 and exhaust Leaks

Richard,

History of the issue–It goes back to 1999 when the 1st DRY manifolds were released on a marine QSM11. Regardless of what you have read and Cummins has claimed to do as to “upgrades”, the issue persists today. Understand there is not a sure fix for this if you need more than about 18 GPH of HP at 2000 RPM to satisfy you need for speed. And even propped that light guarantees nothing as the design of the system is just plain wrong.. As to the heat shield–Yes they are tricky to deal with, but they can be removed and replaced, or tweaked back in shape if needed.

As to the rest, until it’s all apart, you won’t know what needs to be replaced. About the only thing that is better now that is was pre-2015 or so, is that Cummins cut the cost of the manifold to less than 50% of what it was before.. The dry “truck” turbo it still crazy priced though, and the heat shields $$ is in outer space. Also, there is a new laminated exhaust gasket too @ 4X the $$ of the old one– Is it better? No clue.

[Richard Lynch]

Not enough info…

You may be exactly correct however I am aware of the QSM11 Dry Exhaust Manifold leaking issues. I have those as well. I have posted many times of that topic and posted my before and after prop adjustments. Maybe a little over propped still but I have taken 1.5″ of pitch out and reduced my 2000 RPM GPH from 22.5 to 20.5 range.

Again you might be right and these issues are one in the same however I can feel the exhaust coming directly from the Turbo (Exhaust side) Heat Shield on the Starboard engine. I can NOT feel the exhaust blowing through the Turbo on the Port motor. It does feel like the air (exhaust) is coming from both side but I have not removed the heat shield yet. My mechanic suggested that removing that heat shield is tricky and you can easily distort or damage the heat shield. He is trying to get me on the schedule however i am looking for some history and lessons learned on this issue.

Anyway, i do plan to address the exhaust manifold leak issues at some point down the road.

If someone can shed some light on the Turbo (Exhaust Side) Leaking and what that repair entails i would appreciate it.

[Steve Lewis]

Not Enough info ……….

Are you aware of the issues with the QSM as it relates to the Exhaust design starting at the Manifold and working its way back?

The Cummins QSM11 Marine Engine Story

Item #4 says it all……….. If that is a Sea Ray 52 Sedan Bridge in your profile picture, we can pretty much tell you that you are over propped and exceeding the practical fuel burn limit on this engine.

Please take pictures of the entire engine and then focus in on the Exhaust Manifold area and the junction of the Exhaust Manifold and the Turbo. That gasket might be compromised along with quite a few other items.

Do you have fuel burn numbers for your boat from 1800 – 2100 rpm at 100 RPM increments? That will give us on the forum a good idea of what is going on from a heat perspective and where to guide you from here.

Let us know

[Author]

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