Dissapearing coolant

[micky]

I have a small issue with the other engine. I keep coolant levels on the reservoirs exactly on the "full" mark. After using the boat both reservoir's level is over the "full" mark. Starboard engine goes back to the mark but port engine always is 3/4"-1" below the mark and I have to be topping it off. I thought it was air from every time I've disassembled the system but now I'm not sure. There are no leaks anywhere. What can it be, the heat exchanger?? I tried pressure testing the system but after 8 psi, the tester leaks coolant, like if it was too much pressure. I'm thinking of removing it, put a cap on 1 side, fill it with air on the other side and dipping it in a bucket full of water.

[John F.]

I had an issue with a really slow coolant leak that I couldn’t find. I finally figured it out after a I got coolant dye and a black light to show where the coolant was leaking. It was leaking on a hose that I looked at a bunch of times previously, but never saw the leak. Just a thought. Got the dye and light off Amazon for cheap.

[Yannis]

One fingerheight of coolant lost after a few hours of cruising is something very difficult to locate the origin of, like John confirms. A loose elastic tubing, the cap that might leave a minute space for it to evaporate from...
I have exactly the same issue on one motor, I looked through and around ....bottom line, once or twice in the season I add a wineglass equivalent of coolant into the container.
Notice that everything is measured in wineglass equivalents LOL !

[Geebert]

If you dont top it off, will it continue to deplete?
Or will it stabilize at that lower level ?

[micky]

If you dont top it off, will it continue to deplete?
Or will it stabilize at that lower level ?

No idea, I've been topping it off every time I see it off the "full" mark. Today I pressure tested the system at 15 psi for 2 hrs, it went down maybe .5 pound so pumped it back up to 15 psi and left it pressurized until tomorrow to see if it goes down.

[scenarioL113]

I second what Geebert asked.

I would not add any coolant and and Keep an eye on it and see if it continues to go lower. It could be going out the exhaust from the "RAW" water side of the system thru one of the heat exchangers or coolers.

It is NOT uncommon for 2 identical engines to behave differently to be honest...and I heard that from Tony Athens...

On my cummins I have one engine that will have pressure in the cap when I check the coolant and the other engine does not under identical conditions...Obviously when it is cold before I run them. Go figure

I also had a coolant leak because I installed a turbo gasket incorrectly one time. On a Cummins the turbo gasket looks like it can go in any direction or orientation but it cant bc when you look close it is different depending what way you install it. That was a lesson learned...that one took me a while to diagnose and a shitload of google searches...

[scenarioL113]

Notice that everything is measured in wineglass equivalents LOL !

Funny, I use the same kind of glass except it is measured in IPA's...

[Yannis]

Frank, what are IPAs?

[scenarioL113]

India-Pale-Ale

BEER strong beer cheers!

[Carl]

IPA's can be strong at 7%, some are not, some double n triple IPS's can get close to wine in alcohol content. IPS's used to be very hoppy which can be fruity at first giving way to bitter but not always the case anymore.

My understanding is they started out as the beer British sailors took on voyages to India. They added lots of hops to the beer as Hopps are preservatives in addition to flavor and aroma. The IPA's started fruity but as the beer n hops sat on the trip they transitioned more to bitter.

One of my customers had a Home Brew Business on the side in addition to being a Chemist and Chemical Engineer. I started by machining stainless fittings, clamps and assorted items, then got into welding fittings to the 60-quart mash n wort pots.

When dropping jobs off, I had to do what you have to do in business and that meant taking an interest in his business which often meant tasting his latest and greatest. Other times it was tasting the top picks from contests he judged, both local and regional. I got to taste many many brews and learn alot about them. I found I like beer like I like coffee, keep the flavors out aside from coffee. No vanilla in my coffee and no blueberry in my Ales.

Sometime after my buddy opened a Beer distributorship...again I was strong-armed into trying his increasing product line. Poor me, every weekend he'd bring an assortment of Ales, Stouts, IPA's, Pilsners and Wheat beers. Oh, I love wheat beers...and the king of them all for me Doppelbock beers. I destroyed my waistline after two years of "helping him" learn his product line, but boy did I enjoy some of those weekends.

Back to coolant...

[Yannis]

All this discussion about...beers...the nothingest of nothing...
Wine, you can discuss and sip till there's no tomorrow...
You can add ouzo to it in the summer!!

[micky]

Went to check the gauge today and everything was perfect. Still at 15 psi so the cooling system is fine. I replaced the cap with another one (used) I had until I receive the new ones.

[Tony Meola]

Mickey

Hopefully the cap is it.

Did you find out why the first time the tester lost pressure?

[micky]

I really don't know. Its a new tester so maybe the cap wasn't seated right?

[micky]

Last september I replaced the turbo because it had a pin hole. Ran the boat in november and the coolant was at the right level. After running the boat last weekend the coolant level is down again. I ordered the hydrocarbon tester to see if the issue is the head gasket but I doubt it. I'm leaning towards the exhaust manifold.

What do you guys think?

[Tony Meola]

Micky


How much did you lose? If it was a head gasket, I would suspect that you would see steam coming out the exhaust and possibly milky oil. Exhaust Manifold is always a possibility, or you have a leak somewhere.

[Carl]

If that doesn’t give results, maybe we try a coolant dye. I hate intermittent problems…

[micky]

3/4" - 1" down on the reservoir.

I'm going to remove the exhaust manifold once again and pressure test it to 20-30 psi and while its pressurized I'll heat it some with a torch to see if the pressure goes down.

[micky]

Micky


How much did you lose? If it was a head gasket, I would suspect that you would see steam coming out the exhaust and possibly milky oil. Exhaust Manifold is always a possibility, or you have a leak somewhere.

No milky oil and both engines steam while running if its early morning. During the day no steam.

[Tony Meola]

That would leave me to believe that it is not passing out the exhaust. It has to be a leak somewhere else. A leak in the exhaust manifold should also create steam unless it is really slow.

Is it possible that the engine was airlocked and that air passed out on the last run? I had something similar with my Cummins last year after I had to refill on land before I went in. Had trouble getting all the air out and the first two trips out I had to refill the overflow tank. After that I was good.

[Yannis]

Did you check both ends of the tube that connects to the expansion tank?