CAT 3306 overheating

Island Cessna said:

It
If this is the case the engine would have until the bolt came out, and a new bolt should fix it. Hopefully the bolt and its lock washer are comfortably and harmlessly lounging in the oil pan.

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Here is the schema from the parts book I have. It shows the pins being listed there.

Mechanically, the pins are absolutely required as a drive mechanism between the gear and the shaft. The bolt is only there to hold everything together. That said, if the bolt was tight enough, it could work, but not forever as you found out. It’s also possible that the whole thing was put together correctly and with the pins. If the bolt loosened and fell out, so would the pins.

Ken

Recently we were having a similar problem and were scheduled to have the boat put on the yard for an approaching storm. On the yard we noticed that barnacles were covering 50% of the raw water intake. We have a diver clean the hull once every two months, apparently he overlooked the raw water intake. We cleaned it out and when boat was put back in the water the overheating problem was gone. Before you get deep into mechanical trouble shooting maybe have a diver go down and check out the raw water intake. Just a thought....

Turner said:

Recently we were having a similar problem and were scheduled to have the boat put on the yard for an approaching storm. On the yard we noticed that barnacles were covering 50% of the raw water intake. We have a diver clean the hull once every two months, apparently he overlooked the raw water intake. We cleaned it out and when boat was put back in the water the overheating problem was gone. Before you get deep into mechanical trouble shooting maybe have a diver go down and check out the raw water intake. Just a thought....

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Thanks. It is a good idea and that was the first thing I checked. I do the cleaning/diving myself every month.

I will put the repaired water pump back this weekend and I’ll report back.

OverHeating

LeoKa said:

I have done a barnacle flush on the sea water circuit using Rydlyme, over the weekend.
The flush was successful.

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One of the other things to check is to take the end cap off the raw water heat exchanger and rod the tubes. A gun cleaning kit works well for this with the brush. Sometimes pieces of oxidized zinc gets stuck in the tubes. Also plain old mud/muck.

Not sure on the CAT you have but if the raw water circuit goes through the transmission cooler too, in series with the engine heat exchanger, rod that too.

Craig

3306 Overheating

I don't have a 3306 but do have a couple 3208TA CAT's that I had a overheating issue with that gave me a fit.

Idle up to 1500 RPM was fine, anything above that, the Starboard engine would overheat. This was new to me boat that "seemed" to perform OK during the sea trial. After sitting the hard to get some work done, we splashed the boat and took off (St. Pete, FL to Destin, FL)

It was in the evening, a Saturday, when we left - servicing marina was now closed.
Poking around in the engine room while underway, trying to see anything obvious (half closed sea cock etc.), I notice that the hose from the sea cock to the strainer was collapsed "Ha! Easy fix" I thought as I had some extra 1 1/2 hose. Replaced it that night at our first stop. Next morning, all proud of myself, we were in some open water so I bumped up the RPM - Nope- still overheating... verified by upper and lower temp gauges.

Crossed the Gulf of Mexico at 6 knots and finally got back at my home marina. Couple days later, our diver called and said the was checking out the bottom of our boat and found a oil diaper sucked up in the water intake grate of the starboard engine. Said he really had to tug to get it out. Clogged intake - collapsed hose, Yep- that's it - fixed now!

Couple days later took the boat out, bumped up the RPM's and.. Nope - still overheating...

Ran Barnacle Buster through the system, sea trail - nope, still overheating (like steam coming out of the exhaust overheating...)

While going through some old parts that came with the boat, I came across two thermostats (3208's have two thermostats per engine) that were broke - housings had separated - "That's it, has to be" I thought, the ones in the engine, at least one is broke. Drained the antifreeze, took this and that off to finally pull the thermostat cover "Please be broke" I keep saying and...No, they were not broke... I had my buddy helping me and while I was slowly beating my head against the engine block, he pulled them out and after looking at them said "well, there's your problem" Non-CAT thermostats with 210 degrees stamped in them...

Ordered thermostats (185 degrees I believe), put them in and finally ran at the correct temp...

When I purchased the boat, the boat had sat at the dock for two years and the owner, whom I never met, lived out of state.

- Ensure your through-hull is not clogged
- Hose(s) are not collapsing while under power
- Thermostat is not broke/operating correctly

Best of luck -
Gregg

CAT Overheating

Gregg,

So true on the CATs and their thermostats. Another failure point is if the thermos are taken out. That will overheat a CAT quickly. If I remember we had that problem on a CAT3208 where a thermostat was removed. Contrary to normal logic, the thermo opens to heat up the engine bypassing the heat exchanger and closes to force the water through the radiator or heat exchange.

Craig

Coolant drain plug location

Hi LeoKa

I have an old 3306/D333c.

In the photo you can see where the plywood is. If you zoom in you can see a nut at the bottom of the plywood, partially covered. That is the drain.

Water Pump

This is my water pump. Hard to imagine anything going wrong with it. I would take the end cap off the heat exchanger and check out the bundle. Just cost you a new gaskets and maybe o rings. Try and save the coolant its expensive.

waltini said:

Hi LeoKa



I have an old 3306/D333c.



In the photo you can see where the plywood is. If you zoom in you can see a nut at the bottom of the plywood, partially covered. That is the drain.

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Your engine looks a bit different. Mine is industrial originally, but was put in modified for this boat. I have very limited access/visibility to the coolant water pump.

Well Gents, I am happy to report that we are getting closer to complete recovery.
The water pump was put back together. I had the pins and the bolt purchased locally for around $10. The gasket kit was $25. The pins had to be hammered in, since the gear side hole is different. The bolt did not drive in first, because the thread was deformed slightly. After getting a thread cleaning tool, all was fine. The pump was together and looked very solid.
Mounting the pump back was tricky. The mounting bolts can be driven in only in a certain sequence, due to limited space and other parts of the engine. It was also necessary to turn the flywheel, so the the teeth of the pump gear could connect. It was a bit of a hit and miss, but finally it went in. It cannot be done by hand. We needed a plastic hammer to help the pump to slide into place.
I also replaced the thermostat again. This one I have tested myself and I knew it was working. I wanted to eliminate every trouble points, before the engine start.
I filled the coolant system with Rydlyme+water mix about 10/90%. My goal is to clean out any rust in the pipes, if there is some. I will change it to normal coolant/distilled mix next weekend. It takes 11 gallons of mix total.

We started the engine and it cranked up right away. I let it run on idle 700 rpm for 10-15 minutes. It heated up to 145-150F and stayed there. There was decent sea water flow outside. I moved the rpm up to 1200 and ran it for 5-6 minutes. No change. I pushed to 1500 rpm and the temp stood the same. I let it run like this for 10 minutes. No change. Stayed at below 150F. This is about 20-30 degrees lower temp, comparing to what I had for 2 years I have owned the boat.
I’ve measured the coolant elbow temp on the top of the engine in the ER, and it showed 170-176F. The alarm comes on at 195. The two elbows above the thermostat showed about 10-15F difference only. Prior this difference was over 40-50 degrees. It looked very good. I feel much better now and I believe we have located the overheating issue. It was the water pump, which was not connecting properly and spinning at higher rpm. It could only do proper cooling at idle speeds.

I have not taken out the boat yet. I am on a buoy and I need to pump out first. Unfortunately, I have an oil pipe, which is leaking oil. The one, which comes out of the oil cooler and goes down to the oil pump on the block. It needs a new gasket. Hopefully I’ll be able to get it and install it soon. My plan is to go out for trip next weekend. That will be the final test.

No worries, the head can be replaced. $$$ hope it's not needed. It's best to let engine idle to cool it off, as opposed to shutting it down at overheat temps, at least in this case.
If it overheats in neutral, it will overheat faster under load.

Swfla said:

No worries, the head can be replaced. $$$ hope it's not needed. It's best to let engine idle to cool it off, as opposed to shutting it down at overheat temps, at least in this case.

If it overheats in neutral, it will overheat faster under load.

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I just posted the fix story. It does not overheat anymore.

Lepke said:

Often the need to flush the coolant side gets overlooked. Rydlyme also dissolves rust. It's a quick, easy operation to try before throwing

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Thanks again for the suggestion. It worked. Although, the overheating problem was the pump, now the cooling is much better. It does not go higher than 150F at cruising speed. I could never go this low before.
I let the Rydlyme mix in the cooling system for a week and I replaced it yesterday. The test run was very satisfactory.

LeoKa said:

Thanks again for the suggestion. It worked. Although, the overheating problem was the pump, now the cooling is much better. It does not go higher than 150F at cruising speed. I could never go this low before.
I let the Rydlyme mix in the cooling system for a week and I replaced it yesterday. The test run was very satisfactory.

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A week seems long. What does your thermostat look like after that treatment? Is it still functioning OK and what temperature is marked on it?

sunchaser said:

A week seems long. What does your thermostat look like after that treatment? Is it still functioning OK and what temperature is marked on it?

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It was a very diluted mix. About 10/90 %

The thermostat is brand new and it worked fine. It kept the temp at 150F steadily, even at cruising speed. I think it opens at 145F and fully opened at 195F.

waltini said:

Hi LeoKa



I have an old 3306/D333c.



In the photo you can see where the plywood is. If you zoom in you can see a nut at the bottom of the plywood, partially covered. That is the drain.

Click to expand...

Where do you get your belts and how do you identify them?
I have 2 pairs. One pair goes to the alternator. The other pair goes to the hydraulic pump.
I could not find the part numbers in my manual.
I want to replace all belts.
Thanks.

LeoKa said:

The latest:

The new water pump has arrived, but it does not look like the perfect match. Perhaps, some of you can advice me, if this pump can still be mounted on my CAT? See photos.

As of the overheating; the existing water pump is the possible problem. There are pins and a center bolt is missing, as you can see on the photo. The gear would connect to the assembly, but not securely. Since this is the same gear, where the sea water pump is connected to, I suspect that the damaged raw water pump has done further brake down on the water pump, as well. When the engine is at low rpm, the flow is enough to cool, but as soon the rpm goes up, the gear starts spinning and the impeller cannot push enough coolant around. This is our theory.
Of course, the only way to prove it, if I have a functioning water pump. I will talk to the vendor on Monday, but this pump was sold as being compatible with my engine. Hopefully, it will be sorted out and a replacement pump will be coming?
I can see many variations on the web. Maybe there is a way to plumb this to the bottom of the expansion tank, but I cannot tell, because the space is very tight and hard to see anything there.
If any of you had the same dilemma and had to deal with mounting the water pump, please share your solution.

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LeoKa - I appear to have the same 3306 engine with the exact pump. You are correct, the pump that matches perfectly is 172-7777 but is expensive (~$1,600ish) from Caterpillar. I was able to find a good housing on ebay and bought the remaining parts to build my spare pump. I used quality bearings and Cat parts to rebuild the spare. Now painted white and sitting in my spare box if I need it 1,000 miles from home. Might be worth keeping an eye out for another one. There are also parts sourcing websites that you can put a request out for and you might luck out. I almost bought one from one of them, but fortunately asked for pictures and noticed that the casting was cracked where the snap ring holds the bearing into the casting. I was closely following your posting on boatdiesel.com as I had the same goal as you to have a spare.
Craig

Skag said:

LeoKa - I appear to have the same 3306 engine with the exact pump. You are correct, the pump that matches perfectly is 172-7777 but is expensive (~$1,600ish) from Caterpillar.

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I bought the pump from the CAT dealer, but my 3306 is a converted industrial one and there is a unique setup for this pump on the engine. The standard pump will fit fine with a standard engine configuration, but not to this engine. The CAT dealer was searching everywhere and finally gave me a used part, which suppose to fit with the pump and my engine. I hope this is true, as I cannot test it, unless I take everything apart. Hopefully never.

LeoKa - I'm so glad you posted on boatdiesel.com as I read and studied your pictures closely - I certainly benefitted from it - thank you!!. The difference appears to be the size of the ports as you stated. Mine appears exactly like yours. I bought the used housing 6N8412 on ebay (pictured with new parts installed). Everything matches now. As I stated in my post above, I almost bought a used 3N1440 housing but thankfully noticed it was damaged. I don't know what the difference is between the 6N8412 and 3N1440 housing - they look identical.

The 3306 is an awesome engine and should last 30,000+ hours if not pushed too hard. I agree your water pump will likely last a long time. It is huge, tough and proved to be easy to rebuild as well (the rebuild parts are easy to get - bearings, impeller, shaft, seal etc...).

Craig

Skag said:

The 3306 is an awesome engine and should last 30,000+ hours if not pushed too hard. I agree your water pump will likely last a long time. It is huge, tough and proved to be easy to rebuild as well (the rebuild parts are easy to get - bearings, impeller, shaft, seal etc...).

Craig

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Your ER looks wonderful! I wish I had access like this to the front of my engine. Unfortunately, it is positioned next the wall, which makes the access to this pump, pulleys, belts, alternator; very difficult. If I had good access like you, I would venture to remove the pump and test my spare to fit.
Have you purchased rebuilt kit to this pump, besides having a complete spare? If yes, from who?
How many hours you have on the engine? Do you have any recommendations on maintenance?

So far, I had the followings on my engine, besides the regular oil change and coolant change: Governor rebuilt by a CAT shop, (sleeve metered model, it was dripping fuel), valve adjustment, injector replacement, new sea water pump, new thermostat, rebuilt water pump, new belts, new alternator, new starter, turbo connection repair, new hyd pump and valve, new filters.

LeoKa said:

Your ER looks wonderful! I wish I had access like this to the front of my engine. Unfortunately, it is positioned next the wall, which makes the access to this pump, pulleys, belts, alternator; very difficult. If I had good access like you, I would venture to remove the pump and test my spare to fit.
Have you purchased rebuilt kit to this pump, besides having a complete spare? If yes, from who?
How many hours you have on the engine? Do you have any recommendations on maintenance?

So far, I had the followings on my engine, besides the regular oil change and coolant change: Governor rebuilt by a CAT shop, (sleeve metered model, it was dripping fuel), valve adjustment, injector replacement, new sea water pump, new thermostat, rebuilt water pump, new belts, new alternator, new starter, turbo connection repair, new hyd pump and valve, new filters.

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I think I have less than 2,000 hrs on mine. So it will certainly outlast me. I haven’t done any major maintenance except the exhaust bellows that is connected to the turbo. I now carry a spare. Mine was cracked and leaking exhaust in the engine room. The water pump parts I got mostly on eBay (genuine caterpillar packaging) and a couple items from the local cat dealer that were reasonable. The housing on eBay was expensive $500 (I think), everything else was probably $150 (shaft, bearings, impeller, seals). So $650 and I have a perfect match. I do admire how heavy caterpillar builds their old engines - easy to work on and heavy duty. My engine does not have a sea water pump or exchanger in the head tank - I am keel cooled, which helps keep the engine room saltwater free and looking nice. Appreciate your positive comments.