Muddy CAT 3306

[KnotYet]

I will not have time to test it, till the weekend. Work, work, work.

How would you test the alarm functionality? Again, the manual I have is impossible to follow. I tried.

Although, the alarm came on around 185, if I let it run more, the gauge would have gone higher really fast. At least, that what happened last year, when I had a sea water hose burst.

If you can hear the alarm from the E.R, turn on the ignition and, without starting
the engine, ground the suspected temperature alarm wire to the block.
It should sound off if it is a simple normally open thermal switch.
I agree that 185 degrees is awfully cool for a temperature alarm to sound off.

 

[LeoKa]

Getting close...

Today I went to a diesel shop and talked to someone who knows these engines. They also sell parts, which I ordered.
You guys were correct. The device on the top is just a switch and it does what it suppose to do. Sets the alarm at certain temp. I still ordered a new one.
The problem has to be the heat exchanger. One of them. I have two.
The main suspect is the smaller one for the transmission. It is possible that both needs to be cleaned out, but certainly this one first. The reason is; the heat up occurs when the boat is in gear. When in neutral, there is only normal heat. I've tested it this morning. I started the engine and let it warm up to normal temp, which is around 165F in my case. I let it idle in neutral for about half an hour. The temp did not change. Later, I put it in reverse and let the prop turn at idle speed. In about 10 minutes, the temp started to go up. Very slowly, but it went up. It took about 25 minutes to reach 185F, when the alarm came on. I went to the ER and disconnected that switch. The alarm stopped. When I reconnected it, the alarm came on again.
The shop expert told me that it is how it suppose to be. That is the role of the switch. He recommended to start the cleaning with the Trans heat exchanger, since it heats up only when in gear. That is easier to access and remove, so I will do that soon. Regardless of the result, I am planning to clean the big one on the engine, too. That requires preparation. It is a messier job. Plus, I need gaskets. I really hope the smaller one is the real problem, but both needs to be cleaned. I'll keep you updated.

 

[LeoKa]

This weekend I took off the trans heat exchanger. I could not see any blockage. After assembly, I started the main and ran it in reverse. It slowly climbed up to 175F and stayed there. After 20 minutes, I put it in neutral and went up to cruising speed rpm, which is 1600. The outflow of raw water increased significantly, but the temp reached over 185F on the gauge, when the alarm came on.
I have measured the temp on the top of the engine, where the alarm switch is and it was between 205-210F.
Conclusion; the engine will warm up, regardless of being in neutral or in gear. Slowly, but it will.
My mechanic has suggested to me to use Rydlyme. He uses it and it works. It has to be circulated for few hours, or even sit inside the raw water circuit. It supposedly removes all the stuff. I will give it a try this weekend.
Anyone used Rydlyme before?

 

[Solly]

Did you replace the alarm sender and any indication of the temp when it should go off ?? How hot does the temp gauge get when you let it run ? Does it get over 210 degrees ?
Time for some more troubleshooting. How about getting another temp gauge like this https://www.autozone.com/gauges-and...mechanical-water-temperature-gauge/255992_0_0
Screw it in where the alarm sender goes and see what the actual water temp is.
You can't go by the temp of the metal block. The exhaust manifold could be 600 degrees but that doesn't mean it's over heating.
Still, cleaning the heat exchangers won't hurt but I'm not convinced that will solve the problem.

 

[LeoKa]

Did you replace the alarm sender and any indication of the temp when it should go off ?? How hot does the temp gauge get when you let it run ? Does it get over 210 degrees ?
Time for some more troubleshooting. How about getting another temp gauge like this https://www.autozone.com/gauges-and...mechanical-water-temperature-gauge/255992_0_0
Screw it in where the alarm sender goes and see what the actual water temp is.
You can't go by the temp of the metal block. The exhaust manifold could be 600 degrees but that doesn't mean it's over heating.
Still, cleaning the heat exchangers won't hurt but I'm not convinced that will solve the problem.

Good advice, thank you. I will buy one and see what it shows.
Based on what the diesel parts guy told me, the alarm switch works as expected. It should trigger from 195F-210F. It does what it supposed to; I was told. I can still replace it, but let’s see first the gauge you have recommended.
What I could see over the weekend was that the temp did not go higher then 210-212F at the alarm switch. Although, I was stationary and I did not run it for very long. Possibly less then an hour total.
I am afraid to go out and run it for an hour or two cruising. I don’t want to be stuck out on the water with an overheated engine.
Let’s see, if it improves after Rydlyme treatment?

 

[LeoKa]

Still, cleaning the heat exchangers won't hurt but I'm not convinced that will solve the problem.

Here is an interesting list, what can cause overheating. If I had to pick; I’d check the coolant mix, or the after cooler on my engine.
I know that I did not replace the coolant completely, after the new pump and thermostat was installed. Maybe I should have.
I also see burned sections at the exhaust, where it connects to the after cooler. Something there is not completely sealed, or broken. Taking it apart will be a serious job, because lot of things would need to be removed to access it.

https://www.4btengines.com/causes-of-diesel-engine-overheating/

 

[Solly]

I know that I did not replace the coolant completely, after the new pump and thermostat was installed. Maybe I should have.


1) Inspect the Coolant Level:
The most obvious system to inspect upon discovering overheating issue is the coolant level. If the coolant is too low this can allow pockets of air into cooling system. When air gets into the cooling system it will cause a reduction of coolant flow due to the presence of air bubbles. Air flow alone isn’t going to get the job done to keep engine temperatures constant. If you find coolant levels to be too low simply add more coolant to the engine.

This right here... Heat exchanger systems must be full of water. The volume of water is what helps cool the engine too. Plus you could have an airlock at the alarm sender, temp sender, head, and it's not getting cooled.

Fill the heat exchanger and leave the cap off. Run the engine. Some coolant may overflow the fill. When the engine warms up the thermostat will open and the coolant level in the HE will suddenly drop. Put more coolant in the HE. Do that until it stays full and there are no bubbles in the coolant in the HE. Then close the HE and put some in the overflow.

If you want you can use just water to test but it will need drained and filled with antifreeze-coolant. The mix will cool better than plain water.

 

[LeoKa]

I know that I did not replace the coolant completely, after the new pump and thermostat was installed. Maybe I should have.





1) Inspect the Coolant Level:

The most obvious system to inspect upon discovering overheating

I did check the coolant level, before engine start. It looked high enough. I did not check while running it, so I will follow your suggestion.

Although, I have replaced the thermostat, I wonder, if it is working properly? It was new, but not OEM. I have an extra and I am debating, if I should replace it again?

 

[LeoKa]

Today, I tried to build and use a flushing system, but did not work. My fitting was not adequate for high pressure and when I turned on the pump, it blew off the hoses at the transmission heat exchanger.
Does the flushing system has to be built for high water pressure? All I wanted to do is circulating the RydLyme mixture. I will build another one with stronger fitting, but it is difficult to find barb reducer from 1 5/8 to 3/4. My hose on the engine for raw water is 1 5/8 and the pump is 3/4.

Another thing I was not sure about is the direction. The online source, which the base of my flushing setup says that the flow of the flushing should come in backwards, from the outgoing hose. I wonder, if this is accurate and something is stopping the mix coming from the return?
In my present plumbing, I have connected the pump to the small heat exchanger (transmission), which is connected to the engine’s HE. Maybe I need to connect only to the engine’s HE and exclude the smaller one for the flush?
Or, I should just forget about the reverse flow and connect directly to the intake pipe and push the mix through that way?
All these dilemmas.......

 

[Ski in NC]

Are you trying to push your brew through the stationary impeller pump? Water will not flow through that (well not much) unless it is spinning.

 

[Solly]

Thermostat working ? The temp gauge will tell you. When the engine is first started the temp gauge will rise then drop suddenly when the thermostat opens.

https://www.rydlymemarine.com/wp-content/uploads/2019/12/Inboard_intructions_0917.pdf

This says run the solution the same as the raw water. From the discharge of the raw water pump to the exhaust elbow connection. Really shouldn't matter it should flow either way.

Doesn't need high pressure. In fact the solution cleans chemically so it could sit in the HE with no flow and work too. You just want a gentle flow from the bucket, thru the system, and back to the bucket.

For fittings you can go to one of the big box home improvement stores and get the white plastic water/drain pipe fittings. Measure the outside of a coupling to fit the big hose and look for 1 or more reducers to get to 3/4 female threads to take a hose barb. A hose clamp should be enough to hold the plastic in the hose.

 

[LeoKa]

Are you trying to push your brew through the stationary impeller pump? Water will not flow through that (well not much) unless it is spinning.

Yes, that was the problem. I have realized it now.
I will try another method next. Some guys on the web did it through the sea water strainer. Instead of circulating the mix, they suck it into the engine and let it sit overnight. The next day they close it up and start the engine to blow all of it out.
If this does not work enough, I will do the circulating method next. I will remove the impeller at that time.

 

[LeoKa]

Thermostat working ? The temp gauge will tell you. When the engine is first started the temp gauge will rise then drop suddenly when the thermostat opens
https://www.rydlymemarine.com/wp-content/uploads/2019/12/Inboard_intructions_0917.pdf

The thermostat was just replaced with a brand new OEM. I have no way to tell, if it opens, or not? I have not seen a drop on the gauge this morning. The temp went up to 160F. Tonight, I will try to watch this, I just need to look up, when the thermostat should open? I am single hand, so I have to run back and forth between the ER and PH.

I ended up doing the funnel+sea strainer+papertowel+bungiecord setup, without the bucket and hose. There is an online product for this, but I did not have time to order it. I made it work, but it was a bit more complicated. See it here:

Sea Flush

What I did was, I opened the sea strainer and removed the basket. I've inserted the large funnel I bought at Napa and sealed it with paper towel, as you can see on the video. I filled the funnel with the mix and cranked the engine for few seconds. I kept doing this till all the mix was in and I could see the colored sea water coming out outside. It took me about 6-7 times cranking to finish. I removed everything and closed the strainer. I let it sit overnight. This morning, I put the strainer back in and opened the seacock. I ran the engine for about 20 minutes, until it reached 160F. All looked fine, but more running will be needed. Tonight, after I return from work, I will run the engine again and see how it behaves in gear. If there is no overheating, I will run it in neutral at cruising rpm around 1600, which resulted overheating last time. I'll report back.

The reason I went to this route is that I am hesitant to open up sea water connections (or coolant for that matter), due to being on buoy full time. There is no easy way to clean the bilge for any type of water, particularly oily water/coolant and bucket/dinghy/carry it somewhere without a vehicle! There is no disposal option in my area.
This solution did not require any opening, so it was much easier for me. Of course, if I have to drain the coolant, or to replace the sender and thermostat, I will have no choice. I cannot find an easy way on this 3306 how to drain the coolant to a bucket.

 

[LeoKa]

For fittings you can go to one of the big box home improvement stores and get the white plastic water/drain pipe fittings. Measure the outside of a coupling to fit the big hose and look for 1 or more reducers to get to 3/4 female threads to take a hose barb. A hose clamp should be enough to hold the plastic in the hose.

I had the same idea and I build one, but I did not remove the impeller, so it blew it off. Lesson learned.

 

[LeoKa]

Fill the heat exchanger and leave the cap off. Run the engine. Some coolant may overflow the fill. When the engine warms up the thermostat will open and the coolant level in the HE will suddenly drop. Put more coolant in the HE. Do that until it stays full and there are no bubbles in the coolant in the HE. Then close the HE and put some in the overflow.

I ran the engine again, this morning. I checked the coolant level and it was all normal. I left the cup off and started the engine. There was no coolant bubbling out and it stayed the same level.Shut it down and put the cup back on. I ran the engine for 20 minutes. All looked fine.

 

[LeoKa]

Here is my test run I did tonight. It was about 2 hours long.
The results:
7.55 p.m.
Coolant tank cap off, in Neutral, engine starts, 700 rpm idle
8.10
Engine temp is 155F, gear in Neutral
8.20
Engine temp is 175, gear Neutral
8.25
Gear in reverse, 700 rpm
8.40
Gear in reverse, 700 rpm, engine temp 185 on gauge, alarm comes on
8.41
alarm switch disconnected
8.50
Gear in reverse, 700 rpm, engine temp 180 on gauge, no alarm
8.58
Coolant temp checked 150F at tank, gauge temp 180
Some small bubbles, coolant level only moves up and down an inch, but never reaches the overflow, cap is put back on at tank
9.10
Coolant temp 157, pipe at the alarm switch 215, gauge 180
9.16
Gear back to Neutral
9.25
Coolant temp 160
9.26
Running engine in neutral at 1000 rpm, gauge 180
9.35
Running engine in neutral at 1200 rpm, gauge 180
Pipe temp 217
9.40
Coolant temp 167, gauge 180
9.41
Running engine in neutral at 1500 rpm
9.46
Checking coolant, removing cap, coolant blows out bubbling, flows all over the tank,
Gauge 200F
9.47
Engine down to 700 rpm to cool
9.55
Engine off, coolant cap removed, only tiny bubbles no blow out,
Coolant pipe 225F, gauge 200F
10.00
Engine started, 700 rpm, gauge 180F
10.02
Engine off.

It seems that the cooling can handle low rpm, even in gear. I am on the buoy, so I cannot increase the rpm in gear. Only idle in reverse.
Understand that running a diesel in neutral at high rpm is not ideal, but there is no other way to test the cooling, unless I go out. I am afraid to risk any sailing, if the engine overheats again at higher rpm, while underway.
The other thing what puzzles me that the coolant temp was rising slowly, but never boiled. When the engine was running at 1500 rpm and I removed the cap, the coolant blew out. Was there an air mass, which reached the boiling point and wanted to come out?
Perhaps, I need to do this test again to see, if that was the case, or just the engine overheats at higher rpm?
It seems that the alarm switch is giving false signals to the PH. I will order a replacement. The PH gauge was always lower than what I could measure at the coolant pipe.

Don’t hesitate to give me your opinion. Thanks.

 

[LeoKa]

Few photos

 

[Ski in NC]

So you are getting that 216F at the outlet pipe for the thermostat? And this at light load and new tstat? Wonder if there is a problem with your circulating water pump...

Is this keel cooled or heat exchanger cooled?

Is all the cooling plumbing factory original or has it been modified?

 

[LeoKa]

So you are getting that 216F at the outlet pipe for the thermostat? And this at light load and new tstat? Wonder if there is a problem with your circulating water pump...

Is this keel cooled or heat exchanger cooled?

Is all the cooling plumbing factory original or has it been modified?

It is exchanger cooled.
I am not aware of any modifications. I owned it for 2 years. The PO had it for 10 years, but did not sail much. The original builder sailed for 10 years. The 3306 is an industrial engine originally, but was converted to marine, rebuilt in 1996.

 

[LeoKa]

So you are getting that 216F at the outlet pipe for the thermostat? And this at light load and new tstat? Wonder if there is a problem with your circulating water pump.../QUOTE]

I've started a new thread, since this is not the mud problem anymore:

https://www.trawlerforum.com/forums/s6/cat-3306-overheating-51839.html#post897229

 

[Solly]

I see nothing wrong with the test. Coolant temp stays around 180. Depending on what the thermostat is rated at it sounds about right.
Don't take the cap off a hot system. Just like a car radiator a closed system builds pressure when hot. It's supposed to. The boiling point of water increases with pressure.
If it was mine I'd take it out and run it. If the water temp gauge shows it overheating slow to idle and return. As long as it cools down at idle you should be OK.
I don't like the stream of small bubbles in the coolant though. That might mean a head gasket leak. $$$ Maybe time to call in the pros.

 

[LeoKa]

I don't like the stream of small bubbles in the coolant though. That might mean a head gasket leak. $$$ Maybe time to call in the pros.

I would not call it stream. Some, maybe.
The head gasket was replaced in late 2018, when my diesel mechanic friend did a valve adjustment on it.

I'll take her out this weekend and see how she goes.

 

[LeoKa]

It seems that my problem has been solved.
After replacing the sea water pump. Flushing the sea water system with Rydlyme. Removing and fixing the water pump. Flushing the coolant system with Rydlyme. I have perfect cooling at cruising speed.
The problem was the water pump. It was missing the connecting pins and the center bolt, which holds the gear to the impeller's housing. I bought the pins, bolt, gaskets online and mounted it back. The cooling temp immediately went down. Right now, it does not climb higher than 150F. I reward this to the Rydlyme flushing, which must have cleaned out everything.
The water pump could have been damaged by the sea water pump's deterioration, since I did not have overheating problems before.
I will go for a weekend sailing soon, which will be the real test of these repairs.
Thank for all your help.

 

[tiltrider1]

I spent the weekend tied to the dock next to your moorage. Nice view you have.

 

[LeoKa]

I spent the weekend tied to the dock next to your moorage. Nice view you have.

Sure do. Eagle Harbor is a pretty place. I can even see Seattle from my windows. I just wish people would dump less crap into the bay. Sometime when I dive to clean the bottom, all kind of stuff is floating around.