3208 Port engine still getting salt water into the coolant.

[RickyD]

So a year ago February I discovered that I was getting salt water into my coolant. I did not have recovery tanks so the overflow was going into the bilge somewhat un-noticed. So, I pulled the coolant bundle out and had it cleaned and repaired, but since I had to move my air con unit to get it out, I decided to buy a new Caterpillar bundle to avoid this from happening in the future. $2500. Man if I had known in advance I may have stayed with the repaired one. So after putting it in I found I was still gaining water. One our TF followers mentioned that I may have not gotten the starboard side "O" ring on properly and it was leaking. So, I took the end cap off again, replaced the "O" ring and lubed it up really well, and very carefully eased it all back together. That seemed to work. I had not been running the boat much as we were vacationing quite a bit overseas. Then I spent most of this Jan and Feb working on aftercoolers and the starboard coolant bundle. Finally I put recovery tanks on the engines and now I find that my port engine is again gaining water. What have I missed? Where else can I get salt water into the coolant? I'm stumped. I can do the end cap again but what is going to be different. No problems with the starboard engine. Did I get a bad new bundle? Is the end cap invisibly bad?

 

[Mac2]

I have twin 3208s. My coolant level, that I see in the overflow tank, fluctuates tremendously. Sometimes it's way over the normal level, and other times it looks like it's low. Both engines do this. What is your evidence that sea water is getting in the coolant?

 

[RickyD]

Excuse my typically long answers. Well, first the coolant visible in the recovery tank hose started looking weak compared to the starboard. That port recovery tank started to leak a little so I added some coolant to the tank. I ran the engine for some time and it got sucked back into the main tank. So then I opened pressure cap and saw that the coolant was low. I put in about 1 gallon. I'm thinking that with all the flushing I did when I first had the problem there may have been air gaps. So I also added coolant to the recovery tank to the min line. I ran the engines while taking the boat over to the pump out station and back. Then after some cooling period I looked again and the port recovery tank was at about 3/4 high while the starboard was back to the min line. So then I opened the pressure cap on the port side and the coolant was near the top. When I opened it there was no remaining pressure. Then I opened the stb and it gave a little psst. Thinking back I'm not sure if that was vacuum or pressure release. I'm taking the boat out to the islands tonight so I'll get a better idea of any water incursion.

 

[twistedtree]

Did you flush and add new coolant after the repairs? If so, I would draw a sample and send it out for testing to confirm if there is seawater in it.

 

[Mac2]

Did you flush and add new coolant after the repairs? If so, I would draw a sample and send it out for testing to confirm if there is seawater in it.

Totally agree. The overflow tank levels are so erratic, it would take a long time to figure it out based on these readings. I also believed I was having issues with my coolant system based on the varying levels in the overflow tank. I did have issues with the pressure caps. I replaced both as they were leaking. You would think the coolant would go into the overflow tank, but it was leaking (very slow) at the stern side of the cap and running down the engine where I couldn't see it. I now place a piece of paper towel behind the cap, so I can see if any coolant is coming out of the cap.

 

[heysteve]

Perform a coolant pressure test on both engines. It's simple and quick. The devices can sometimes be borrowed or rented from auto parts stores.

 

[RickyD]

Perform a coolant pressure test on both engines. It's simple and quick. The devices can sometimes be borrowed or rented from auto parts stores.

Great idea. Thanks.

 

[RickyD]

I have not pressure tested nor chemically tested the port coolant yet. One reason for concern is the appearance of the fluid in the recovery lines. Port obviously less colorful compared to stbd. So I ran the port engine while pouring in more coolant and I was surprised that it took 1.5 gallons. So I closed it up and observed while we took a 50 mile trip. I didn’t gain in either engine. So I’m still watching. If I send out samples for testing who should I send it to? I have sent some to Blackstone but they didn’t really test for salt as I recall. They told me they are set up for oil testing not coolant.

 

[RickyD]

Ok, I called Blackstone and they test the coolant for oil not water or salt. Caterpillar does test for chloride.