Official Caterpillar3116/3126 Thread

ttmott said:
Fuel cooler location -
View attachment 131115
Click to expand...
The marina service owner, not a diesel mechanic but owns a diesel boat himself and services the Boat US diesel powered tow boats slipped at the marina, which spend a lot of time in mud, says I need to flush/check the fuel coolers. From what I have heard here that is mostly not likely the source of my issue. But it is the first stop after the seacock/strainer and before the raw water pump.
  1. Do you agree with him?
  2. If yes, getting to the port one will be a challenge, it's located next to the stringer along side the bottom of the engine. Getting to the starboard one, even with removing the exhaust hoses, looks almost impossible. Suggestions/tips/trick to do this?
  3. I assume it's a clamp or two on each end, loosen them, wiggle it off, flush it at the dock, reinstall?
Thanks
 
mrsrobinson said:
The marina service owner, not a diesel mechanic but owns a diesel boat himself and services the Boat US diesel powered tow boats slipped at the marina, which spend a lot of time in mud, says I need to flush/check the fuel coolers. From what I have heard here that is mostly not likely the source of my issue. But it is the first stop after the seacock/strainer and before the raw water pump.
  1. Do you agree with him?
  2. If yes, getting to the port one will be a challenge, it's located next to the stringer along side the bottom of the engine. Getting to the starboard one, even with removing the exhaust hoses, looks almost impossible. Suggestions/tips/trick to do this?
  3. I assume it's a clamp or two on each end, loosen them, wiggle it off, flush it at the dock, reinstall?
Thanks
Click to expand...

I think it's sound advice to check off each item in turn.
Can't you back flush from the hose that goes to the raw water pump?
 
mrsrobinson said:
The marina service owner, not a diesel mechanic but owns a diesel boat himself and services the Boat US diesel powered tow boats slipped at the marina, which spend a lot of time in mud, says I need to flush/check the fuel coolers. From what I have heard here that is mostly not likely the source of my issue. But it is the first stop after the seacock/strainer and before the raw water pump.
  1. Do you agree with him?
  2. If yes, getting to the port one will be a challenge, it's located next to the stringer along side the bottom of the engine. Getting to the starboard one, even with removing the exhaust hoses, looks almost impossible. Suggestions/tips/trick to do this?
  3. I assume it's a clamp or two on each end, loosen them, wiggle it off, flush it at the dock, reinstall?
Thanks
Click to expand...
Never leave a stone unturned as they say.
The cooler is held in place with a bracket and two bolts into the engine block. Disconnect and cap the fuel lines. close the seacock and pull the hose from the end of the cooler then remove the cooler attaching bolts and pull the cooler from that short piece of hose to the raw water pump. Less than an hour to do all. You will find that this cooler is a straight through piece of pipe; it doesn't have the tube bundle structure like the other coolers.
So, let's see - how old is the boat? maybe time to replace those hoses, couplings, and clamps while apart....

Just a question - have you systematically gone through all of the flow paths for the raw water side of things?
If so, then I'd suggest that you put a 5-gallon bucket next to the engine and route a 2-inch hose from the gear cooler outlet to the bucket then start the engine and see how fast it fills the bucket at idle then do it again at 1200 and again at 2000 RPM. It'll take two people as at the higher RPM's the bucket will/should fill fast. What you are looking for is parametric increases in flow that shows the water flow is increasing and generally un-impeded.

Or as an edit simply remove the supply hose and look into or get your cell-phone camera photo of the cooler.
 
Thanks @ttmott and @SCFoster

Yes, I can backflush. While the trans coolers we off I back flushed from the inlet side to the raw water pump side. The dock has amazing pressure. All clean/clear water came back. I flushed thru the exhaust side as well, same thing.

Boat is 21 years old, my guess is the fuel coolers have never been touched before, but just a guess. That was my observation when removing the trans cooler, I saw no paint flaking/chips. Though, that said. the port transmission was replaced 2 year's ago. The invoice said "cleaned trans cooler" so I assume they had to remove it, but who knows.
 
I was down in the ER today poking around with them running and noticed a couple oddities with the port engine. This engine runs perfectly fine, good oil samples, etc.

1) whispy smoke/steam from the breather. I’ve never actually looked for this so it might be normal. It’s not excessive by my estimation but I also have nothing to compare it to

2) lower idle oil pressure than the starboard. It idles around 30psi after a good run and the engine is completely up to temp.

has anyone ever looked that closely at the breather, and is some amount of steam a normal thing?

I also want to drain the oil down a bit as I think it might be a little high per cats recommendation. It is right at the full mark after it’s settled for a couple minutes post shutdown. I think slightly overfill could equal blow by?
 
My oil pressure at idle, especially after running the engines, is 25 or less, per my brother-in-law caterpillar mechanic that's fine. At the dock when I first start them up they're around 50, after I come off plane they dropped to 25.
 
mrsrobinson said:
My oil pressure at idle, especially after running the engines, is 25 or less, per my brother-in-law caterpillar mechanic that's fine. At the dock when I first start them up they're around 50, after I come off plane they dropped to 25.
Click to expand...

thanks, that’s reassuring. I looked back at old dash videos and they’ve always been that way so I don’t think that part has changed. It does fluctuate up and down just a tiny bit (1-2psi) but I figure it’s a mechanical pump so that could happen

The little breather smoke freaked me out a bit.
 
You could definitely be getting some smoking out of there if the oil is at the full mark.

I have had a few boats that will use oil until they get to their preferred level. Usually that level is about the middle between the add and full mark on the dipstick.

My friends 800 - 3406 Cats would use quite a bit of oil if overfilled at kind of an alarming rate, once it settled in at the correct level it wouldn’t budge from that level on the dipstick for 100+ hours.
 
Carver370 said:
You could definitely be getting some smoking out of there if the oil is at the full mark.

I have had a few boats that will use oil until they get to their preferred level. Usually that level is about the middle between the add and full mark on the dipstick.

My friends 800 - 3406 Cats would use quite a bit of oil if overfilled at kind of an alarming rate, once it settled in at the correct level it wouldn’t budge from that level on the dipstick for 100+ hours.
Click to expand...

thanks. That’s what’s interesting is they burn zero oil from what I can tell but I’ll pull some of.

honestly, the smoke is so slight it might have always been there. The sun was hitting it just right so I noticed it
 
Strecker25 said:
thanks. That’s what’s interesting is they burn zero oil from what I can tell but I’ll pull some of.

honestly, the smoke is so slight it might have always been there. The sun was hitting it just right so I noticed it
Click to expand...
As I understand it these engines need to be filled with oil between the Low and Mid points on the dipstick. Between the movement/attitude of the boat and the windage from the crankshaft there will be a lot of oil mist if too full. The second thing to do is clean the oil separator. If you are seeing a mist coming from that little filter then oil is being introduced in the compressor side of the turbocharger.
 
ttmott said:
As I understand it these engines need to be filled with oil between the Low and Mid points on the dipstick. Between the movement/attitude of the boat and the windage from the crankshaft there will be a lot of oil mist if too full. The second thing to do is clean the oil separator. If you are seeing a mist coming from that little filter then oil is being introduced in the compressor side of the turbocharger.
Click to expand...

i just pulled half gallon off both sides and it’s still at the midpoint so definitely overfilled. I’ll give her a good run tofay
 
Before I continue to spend time and money chasing down a raw water overheating issue, could I have damaged both engines when they overheated, and if so how can I test for that? I used to do leak down test on gas engines, is there such a test for diesel to check for damaged heads, block, cylinders etc?

I'm making an assumption that they start okay, they still run strong and such, just start to heat up at higher RPMs, and the reason is a blockage in the raw water system, is that a bad assumption? I haven't seen any signs of mud so far, so really starting to wonder how much could have gotten all the way to the heat exchangers and after coolers and that's the issue.
 
mrsrobinson said:
Before I continue to spend time and money chasing down a raw water overheating issue, could I have damaged both engines when they overheated, and if so how can I test for that? I used to do leak down test on gas engines, is there such a test for diesel to check for damaged heads, block, cylinders etc? I'm making an assumption that they start okay, they still run strong and such, just start to heat up at higher RPMs.
Click to expand...

CAT has a specialized meter to check blow by rate, which is the widely accepted test to determine engine wear.

you can check compression on a diesel but I heard no one does because you need a gauge capable of measuring those pressures and you have to remove the injectors to do it

I was told by the cat guy who did our survey that these boats need all the power the engines can give so if there is a significant loss of power, a bad injector for example, you know it right away because the performance of the boat tanks very quickly.

not like with our gas powered 290, we ran on 7 cylinders and I barely noticed a problem
 
Okay, good to know so far, because the performance has been the same as before the mud event. Curious to know what others think.

I asked my girlfriend's brother-in-law and he thinks they're ok. His background is land and heavy equipment though, not marine.
 
Update on the breather thing: I pulled that 1/2g of oil out of each engine to bring the resting dipstick level to the mid mark.

I didn’t get a chance to run them up to full operating temp but I no longer have any smoke/steam from the breather. I pulled off the hose and even put my hand over the breather outlet for a moment and nearly zero pressure builds telling me there is minimal blow-by

immediately after shutdown the oil level is right at the low mark and creeps back up to 1/2 after it all drains back to the pan. A full temp run will confirm all this but the moral of the story is don’t fill the damn thing so much :)
 
I put about 1600 hours on my 3116's and never had any blow-by or visible fumes from the vent system.

There are some differences in the way I managed my maintenance compared to the above:
1. I have several diesel engines I maintain: a 6.5 GMC turbo diesel in a work truck, 2 4-BA Cummins engines in Case Backhoe and dozer, 3 Kubota tractors and a Kubota 4cylinder in an air compressor + the 2 Cat 3116's in the boat. I understand not overfilling the engines with oil but filling each one of the above to some level other than the full mark on the dip stick (most only have a full mark) is a management problem because I just cannot remember the level that I filled each engine to at it's last service, so they are all filled to the full mark. Maybe I am lucky but none use any oil, except the GMC which leaks a drop or 2 from the rear main seal after a long run.

2. I use thicker Rotella T1 SAE-40 in the Cat 3116's
3. At 1600 hours, my 3116's have never used any oil and have never leaked a drop.
4. I bought the boat with 75 hours on the engines and my first oil change removed the Cat break-in oil an replaced it with SAE -40 and that is all they have ever had in them.

5. Again, maybe I'm just lucky……………..
 
Per the GFs brother-in-law there is a way for them to test for a head gasket issue using a special radiator cap and a hose, that's what they use in the shop. He said these engines are such high compression if there was a head, cylinder or internal issue you would know it.

He also said the yet to be installed replacement thermostat/ regulators I purchased from cat are 190 so he doesn't understand how the engines were running at 180 prior if that's what's in there now. He also states for the land equipment running just under or at 200 was okay.
 
I believe they originally used a lower temp thermostat but now recommend (offer) the 190's. That may be why they are reading 180.
 
Anyone know what the fuel return line fitting is coming off the fuel cooler?

I want to make up a small piece of clear hose so I can check for air in the return. I watched the cat tech do it on our other engine when the injector cups were replaced (combustion gasses running past the seals) and I would like to check the other engine once a year or so in case the other ones start leaking as well

The other test is to stick a hose in a bucket and watch for air bubbles in the return fuel but that's just asking for a mess imo
 
You must log in or register to reply here.

Forum statistics

Threads
113,253
Messages
1,429,373
Members
61,133
Latest member
Willbeckett
Back
Top