QSC 8.3 Turbo soot, aftercooler cap grease leak

[Brad Arrington]

I have a new-to-me 2019 Back Cove 37 with a QSC 8.3 600 engine. 157 hours. Recently picked it up in Charlestown, SC and drove it 981 miles up the ICW to Long Island. Pleased to say the fuel burn was a spot-on match to the Cummins fuel demand chart.

Checking things out post-trip, I noticed 2 things I’d like to understand:
1) There is some sooty-type material on the turbo near the wastegate.

There is what looks like a heat shield over the end of the turbo on the exhaust side that also partially covers the wastegate. There is sooty material under there, but it has also leaked out from under there and deposited on the wastegate bracket and some areas forward. Some of this fine powdery material is black, but it also has a rust colored hue.

2) Grease is leaking from under both aftercooler caps.

On the port side of each aftercooler end cap, roughly in the middle, there is black grease leaking out. What’s going on here?

And before anyone mentions it from the virgin red paint on the caps, the prior owner had not changed the zincs. I noticed these issues while installing new ones last weekend. The HX zincs had a bit of life, the AC zincs were just shells that crumbled, and the gear oil cooler zincs were gone down to the caps.

Topic

[John]

I wouldn’t wait to do the AC, though very unlikely there’s any issue but it’s a relatively easy item to do given all that room and a small price to pay to get the peace of mind.

There’s no grease or other lubricants in that area, other than what was used to assemble the AC when new.

Maybe, possibly, being pushed out due to some beginning corrosion taking place, but being so new, unlikely in a terrible state at all.

Get it done now while easier to do, just to know for sure. You’ll have to do it anyway next year for sure

[Brad Arrington]

Thanks for the link to the soot issue. Seems like a call to my local Cummins service guy is in order for that. I’d think it would be covered under the warranty.

As for the aftercooler grease, understand about getting them serviced for a baseline. I’m curious what what would cause the grease to leak out there, and if it’s likely to be a significant issue. In other words, can I wait a while to get the baseline service, or get this looked at ASAP?

[Steve Lewis]

Waste Gate Soot is a known item. You can start to read about it here

https://www.sbmar.com/community/topic/heavy-soot-around-turbo-wastegate/

As for the Aftercooler, I would want to get it serviced. 2-3 years in Salt depending on boat build date. Check out Tony’s tips on Aftercooler maintenance as that is an important item in the life of the engine. Service Interval on the Aftercooler in Salt Water is important. You can also add a fresh water flush quite easily since you have nice easy access in that engine room.

It is worth your while to have it serviced as per the SBMAR protocol and have first hand knowledge that it is in a known good state and then stay on top of the interval.

2 users thanked author for this post.

Brad Arrington, Tony Athens

[Brad Arrington]

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[Author]

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