Servicing Aftercoolers on QSM11 Cummins

[Curtis J McNamee]

I am looking at a 2002 Bayliner 5788 with twin QSM11 Cummins engines with 3,900 hrs on them. Just finding out that the aftercoolers have never been serviced, the owner says the engines run cool and there are no leaks.

What is the recommended service interval for these coolers and what kind of shape do you think they are in now with 3900 hrs of salt water use in the Pacific NW.

Any suggestions would be appreciated.

Cheers,

Topic

[Larry Backman]

3 year interval for me

I’m on a religious 3 year interval for the entire set of 4 coolers.

I would expect the worst on all your coolers if they haven’t been serviced in all those hours and assume you will minimally have to replace the AC if not all 4 of them

I picked up a boat with 600 hrs on the engine over 8 years and when we went to service the coolers found corrosion had almost destroyed both the AC and the HX. Tony saved them, but the AC lost a bunch of fin material and both the HX and th AC had severe housing corrosion that required special sealing.

Personally I’d assume your going to have to put at least 10K, possibly more into each engine to make them right. If the cooling circuit hasn’t been touched, what shape do you think the turbo, the exhaust elbow, the alternator and the starter are in?

[Author]

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