Caterpiller c18 1000 hour service

It may not be a hour issue, or operating water; just the age.
Any history of the charge coolers getting replaced before?

If those are original charge coolers, I would recommend replacing them also.
Pat on them with a smile, they have been good for 17 years.
They usually last 5 years.

The 1000 hour service is EVERY 1000 hours. You need to clean all of the coolers. There are many......heat exchanger, aftercooler, transmission cooler, oil cooler, fuel cooler etc. Aftercoolers should be REPLACED every 6 years.

Has it been 6 years already?
Time flies when your having rum..

The Cat guidance is 6 years replacement and every 2 years removal and pressure test for salt water use. For fresh water they recommend removal clean, pressure test and inspect without the strict 6 year replacement requirement. My current boat has C-18s and was in Wisconsin for several years, without aftercooler replacement, so I had concerns and wanted to build replacement costs into the purchase. I was provided Cat documentation explicitly stating the fresh water guidance which I can post if you want.

When I took ownership, the first thing i did was have the aftercoolers out, cleaned and tested. As it happens one had been replaced 4 years earlier and tested fine so I kept it and replaced the other. After 2 years they will come out again and I will relace the other one as it will be at 6 years since new. I did have my mechanic rebuild the heat exchangers and replace thermostats to be safe and thorough.

If I were you, after 17 years, I would replace both aftercoolers if original. I would add that I had 3208 Cats in my previous boat and at 3000 hours and 25 years old, I had replaced the aftercoolers twice and they were ready again to be replaced when I sold the boat last year. At each replacement I tried to push it a couple years to 8 years and each time there was evidence of failure beginning. I do believe the new style C18 aftercoolers are much better than those on the 3208s.

They're not. Dealing with an issue right now on 15 month old C32's and looks like 1 aftercooler may potentially be leaking and have 4 liners with rust pitting. If they're not leaking they sure as heck don't look to be less than 2 years old.

Here is the snip from the Cat document

Keep us posted on the outcome with the C32s. That is the first I have heard of problems with Cat aftercoolers that are almost new.

The reason I like the new C18 aftercoolers compared to the 3208s is the C18s have a valve on the bottom that is normally open and closes when the engine starts due to intake pressure, and the AC sits vertical on the side of the engine. That valve lets any condensation or fluid in the aftercooler housing drain out to the bilge. On the 3208s the ACs sit on top of the engine and any residual fluid or condensation drips directly into the engine intake. I know someone in MD that had a slow AC leak that accumulated water into the engine over the winter and on spring start up he water locked and threw a rod destroying the engine. It is important to make sure the AC housing valve operates freely.

We had a customer with a replacement C32 cooler leaking after 16 months. Thank goodness for extended warranties and (then) a great Cat service manager/shop.
Like I have mentioned be before, New don't mean squab..

Try calling Marcello at South Shore Diesel in Miami. He specializes in Cats. He did my aftercoolers and heat exchangers last year for a reasonable price.

60K seems high for 1000 service plus aftercooler replacements. But 15K per engine for complete 1000 hour and 20K for both aftercoolers replacement is possible.

I think I uploaded the file here, I could not do it in the PM.

That was the wrong file. This post should have the AC service material.

They are good. N+G engineering in Hollywood,FL is also very good and who I've used for 20 years. $100k sounds very high.