Anti Freeze Consumption 6CTA ?

[Bill Desmarais]

I’m posting this question for a member here and on downeast boat forum.

He owns a 35 Duffy downeast tuna boat with a 2014 6CTA 450 with 1300 +- hrs on it.
It’s a 2014…new ReCon…..nothing “un-factory” about the engine.

He discovered recently that the engine is passing raw anti-freeze. He noticed some un-burnt green anti freeze came out the exhaust on startup and checking the big expansion tank (it was low) on anti-freeze.

He figures the engine is losing about 1.5 gallons of anti-freeze after 6-8 hrs of engine operation. 30-40 miles out and back running at cruise rpms.

Other than the loss of antifreeze, the engine runs flawlessly. The owner is pretty hands on
with the Cummins 6BTAs and 6CTAs.

He asking where he should search for the leak.

1. Turbo Flange gasket ? Or would the anti-freeze “burn up” with the hot exhaust.
2. Leak in the heat exchanger ? Engine is 4 yrs old…seems soon for a leak?

Any ideas?

Topic

[Dan Doumani]

Thank you Tony. I will replace the turbo gasket today. What is the manifold cap?

That is correct. The motor did not overheat

[Rob Schepis]

Just to confirm – No history of an overheat, right?

[Tony Athens]

Start here……………………………….

How to Repair a Leaky Turbo Gasket on a Cummins Marine QSC 8.3 Engine

RECON assembly can leave room for improvement..

I would also do the manifold “cap” too at the same time.

Changing a Turbo to Exhaust Manifold Gasket on a Cummins Mid-Range Engine

Tony

[Author]

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