Coolant Loss 3116 Cat

[Pour Excuse]

Hello All
We took a cruise up the lake yesterday on the "Pour Excuse" 97 40' Sedan Bridge. I ran the engines up to 2800 rpms for 3-5 minutes and then continued back to sightseeing at 1400 rpms.
A few minutes later the over-temp alarms went off. As we had never had an alarm go off it took a couple minutes for me to shut down the port engine. We were over 200 degrees on the port engine.
We returned to the slip on the remaining engine until we docked. I ran the port engine long enough to dock the boat. The temp remained bellow 180 degrees.
Doing some investigation :

I checked the strainer and it was clean.(so much for the easy stuff)
Raw water wast running freely from the exhaust
I checked the coolant level it was empty in the overflow and tank.
We restarted the unit and my son noticed red stuff(Cat Coolant) coming out of the exhaust along with the raw water at the start up.
We are not producing smoke of any kind
The oil does not show any sign of coolant contamination.
There is no sign of external leaking in the bilge.

I sure could use some expertise as to where to start on the troubleshooting. I am fairly proficient at wrenching and understand somewhat the cooling system(I think).
Possible Failure points?

Head gasket
Turbo housing
Heat exchanger
Exhaust manifold

I sure could use some help determining what the issue is and how to isolate the issue before I get the checkbook out.
Thank You

 

[Irie308]

Sounds like you may have lost your coolant to the raw water side. Not familiar with cats but would start with looking at the heat exchanger. Pressure test it perhaps?

 

[dtfeld]

I would start ruling things out first.

Get your hands on several CAT SOS kits and take samples of the coolant and engine oil. The will be able to quickly identify any cross contamination, and help point to the issues, or if fluid changes are warranted.

Any history of salt water use? Any idea if the cooling system has ever been descaled? When were the anodes last checked /changed? History of the ELC being tested/replaced?

My first inclination in the Heat exchanger. There could be several cross contamination points including the orings or the tube bundle failed. Since you’ve already lost coolant, you could go ahead and drain sample the coolant.

Pulling the entire heat exchanger isn’t hard. You’ll likely need to pull the expansion tank first.

You could then pressure test the unit as a whole , or pull apart and see what you have.

Once your this deep, I would replace all hoses on the coolant and fresh water side as well as new ELC.

If an oring failed, the are cheap. The tube bundle isn’t.

 

[Riptide III]

I agree with the above. However, before you start pulling it apart I would pressurize the system FIRST. it may be easier to determine the cause before disassembling. Possibly isolate the expansion tank and heat exchanger from the engine.

 

[Pour Excuse]

Thanks for the quick replies
Update: Yesterday I rented a pressure tester and determined there is a leak in the system while the coolant level was low.
I refilled the system (5 gallons) and tested again to test when full.
Noticed the same rate of pressure loss. 20 minutes to go from 13 to 0.
I tried to start the motor and it would not turn over and I am afraid that it may be hydro locked. It started without issue after the over heating event.
Going to separate out the sub systems and test them separately. I am fearing a head or manifold issues.

 

[Riptide III]

I would get a mechanic out there right away. If you have water in those cylinders and don’t tend to that immediately, you’ll be looking at a new engine. Forget about the cooling system. That is no longer important! it Is possible you pumped several gallons of coolant into the engine when you refilled the system. Please tend to the coolant in the engine first.

 

[Pour Excuse]

Hello All
Here is an update on the coolant issue we had.
I began by starting to disassemble the individual components and only got to the turbo and found the leak. Water had been laying up in the very bottom of the housing and over 25 years finally let go.
II have purchased a new turbo and am having the aftercooler cleaned and tested. The remainder of the coolant system tested ok.
The fluid had seeped into the cylinders through the exhaust manifold causing the hydrolock condition.
I have rolled the motor over by hand and will crank it with the starter before turning on the fuel.
I pulled the antifreeze from the bottom of the pan with a vacuum pump and oil change pump and will change it again after a short run.
I can only assume the turbo on the starboard engine will need to be replaced soon.
I tried to purchase the turbine housing only as the turbo was in good condition(1200 hrs) but could not find one. If anyone knows where these can be purchased I would appreciate the info.

 

[dtfeld]

Bad turbo housing? that's a new one…

 

[Strecker25]

I’m not sure I follow, you’re saying the compressor housing or turbine? We’re you able to tell if it was raw water, or coolant?

 

[Pour Excuse]

Its on the turbin side in the water(coolant) cooled housing.
Water had pooled at the bottom of the housing. I am assuming it it is from condensation or splash back from the exhaust cooler elbow.

 

[Michael Striplin]

I would get a mechanic out there right away. If you have water in those cylinders and don’t tend to that immediately, you’ll be looking at a new engine. Forget about the cooling system. That is no longer important! it Is possible you pumped several gallons of coolant into the engine when you refilled the system. Please tend to the coolant in the engine first.

O

Its on the turbin side in the water(coolant) cooled housing.
Water had pooled at the bottom of the housing. I am assuming it it is from condensation or splash back from the exhaust cooler elbow.
View attachment 155654View attachment 155653

test that elbow too. They are known to go bad.

 

[Strecker25]

Iif you have raw water in the turbine side the only source is from the raw water cooled riser since, as you show in that picture, the turbo housing has engine coolant in it.

Reading back the original post I’m thinking maybe your turbo housing failed, blew coolant out the exhaust, and caused your overheat/loss of coolant in the expansion tank. I haven’t had our turbo apart in a couple years and don’t recall how it could easily leak coolant (the cartridge isn’t sealed to the housing if I remember correctly) but years of corrosion could certainly eat through it.

If there are traces of raw water in addition to coolant, that adds another layer. As mentioned , would test that exhaust riser first since a pinhole leak would dump raw water into the housing and potentially into the cylinders. (Maybe a cause of corrosion ultimately eating through the housing, causing the coolant leak?)

In your pressure test, was the turbo the source of the pressure leak?

Either way it sounds like a new turbo is in order id just want to be sure the whole system is sealed and sound so you don’t run into it again shortly after reassembly.

 

[Pour Excuse]

Thanks for the reply Ryan
The turbo proved to be the leak in the coolant side but I do not have a clear idea as to how the raw water was to lay in the exhaust side. The corrosion where the hole was in the turbin housing was at the very bottom of the housing leading me to think that it was condensation or somehow water splashing back from the end of the exhaust elbow. There is a drain from the bottom of the supply hose that goes tot he propeller shaft seal and this would keep water from creeping up the turbo?
I will try to figure out how to test the exhaust elbow as it could have a leak in the raw water side. I haven't had the elbow off to examine how it works. I can only assume that the exhaust is open to the remainder of the exhaust stem after the elbow?

 

[Michael Striplin]

Cat recommends running 190 degree thermostats rather then 180 that used to be recommended.

 

[Michael Striplin]

Thanks for the reply Ryan
The turbo proved to be the leak in the coolant side but I do not have a clear idea as to how the raw water was to lay in the exhaust side. The corrosion where the hole was in the turbin housing was at the very bottom of the housing leading me to think that it was condensation or somehow water splashing back from the end of the exhaust elbow. There is a drain from the bottom of the supply hose that goes tot he propeller shaft seal and this would keep water from creeping up the turbo?
I will try to figure out how to test the exhaust elbow as it could have a leak in the raw water side. I haven't had the elbow off to examine how it works. I can only assume that the exhaust is open to the remainder of the exhaust stem after the elbow?

The riser is known to cause this exact problem and the leaks in them can be very difficult to locate

 

[Pour Excuse]

Looking at the exhaust riser, I don't see any way to repair these.
Would a replacement be the only solution?

 

[ttmott]

Cat had, at one time, put stainless steel risers on the 3116 engines. There was a problem with cracking and corrosion. They changed to bronze and all should have been changed over. There was a bulletin on the issue. Check to see if yours happen to be stainless steel. The risers are raw water jacketed and turbocharger engine coolant jacketed.

 

[Strecker25]

Ours thankfully are bronze, insanely heavy for the size. Once you get it apart you’ll see but that are difficult to test since the raw water exit is from the “shower head” where it mixes with exhaust gas and should be heading downhill from there. Make sure there is a slightly downslope to your exhaust hosing, someone could have put the 90* stainless elbow on wrong which would cause condensation or water to run the wrong way. It would take quite a bit to overcome the riser slope, but it’s possible

 

[Michael Striplin]

Ours thankfully are bronze, insanely heavy for the size. Once you get it apart you’ll see but that are difficult to test since the raw water exit is from the “shower head” where it mixes with exhaust gas and should be heading downhill from there. Make sure there is a slightly downslope to your exhaust hosing, someone could have put the 90* stainless elbow on wrong which would cause condensation or water to run the wrong way. It would take quite a bit to overcome the riser slope, but it’s possible

The bronze one get pinholes

 

[Maybe A Dancer]

One of the MANY reasons to fresh water flush and wrap up with a dose of SALT AWAY.

BEST !

RWS