Aftercooler core possibly leaking?

[Grant Robarts]

I posted this over on boatdiesel, but then I remember this forum. Anyway…

Got back from 3 days on the water and was able to do a thorough search through the engine room. I noticed a tiny bit of greenish water settled in some corners on top of one of the aftercoolers. (QSB550s) Searching around, I noticed what looks to be some greenish liquid sprayed from the air side of the aftercooler going to the intake. I disassembled the aftercoolers about 6 months ago and had the cores cleaned and pressure tested. All was good then. I reassembled with the rebuild kit, using a lot of the Metallube on all seals. I couldn´t see any evidence of water leaking from the drain below the aftercooler housing. Attached is a picture. NOTE: The spray was originally more evident than in the picture, but like a dummy, I wiped it off before I took the picture.

Any ideas, before I take everything apart this week?

Topic

[Tony Athens]

QSB 6.7 550's

Get back farther and show the entire area and the engine..

Total current hours?

When you say you dissembled the aftercoolers– On the engine? Off the engine? What exactly did to take apart? Any pics of your work?

S. Calif– Where did the engines come from?

Who installed them?

In-service date? ( the date they saw saltwater and you started using the boat/engines)

Where were they seatrialed and by who?

New vessel or repower?

Tony

[Author]

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