Coming back together nicely! Aftercoolers were a bit of a pain to line up because the hoses go in all directions. A little dawn on the coolant hoses helps matters along.
Official Caterpillar3116/3126 Thread
- Thread starter carterchapman
- Start date
Carver370
Well-Known Member
- Mar 30, 2007
- 1,927
- Boat Info
- 2000 Sea Ray 400 Sundancer - Diesel
- Engines
- T-3116 CAT - 350 HP
Anyone have any thoughts on cleaning the aftercoolers with Hydrosolv vs boiling them out by a radiator shop?
I’d consider that next time. I had the shop do it because I wanted the air and water side cleaned but the truth is my water side was in very good shape because were fresh water. I’ll probably make this an every other season job to remove, inspect, pressure test, and clean as necessary and I could see hydrosolv doing a fine job.
curious, which product do you prefer with hydrosolv in it? It seems like many of the citrus cleaners have it as the primary agent
Carver370
Well-Known Member
- Mar 30, 2007
- 1,927
- Boat Info
- 2000 Sea Ray 400 Sundancer - Diesel
- Engines
- T-3116 CAT - 350 HP
I think we are going to give it a try this time. I do not have one picked out yet but I have been researching it.
My main reason to pull them is I have been chasing a fuel knock on cylinder #1 and have tried just about everything to get it to go away including a new governor, six new injectors, and a new rack along with resetting the overhead numerous times. Caterpillar loves me. The engine runs perfectly otherwise but it drives me nuts. The only thing they can think of is that the passageway near cylinder 1 is slightly clogged and when its under boost it performs normally.
We pulled a plug from the top of the aftercooler and there is definitely some sludge in there from a prior owner running 15W40 in them. I now run straight 30 wt.
interesting, my port side also is slightly louder at idle (or was last year before all of this work) so we’ll see what this year brings now that the intake side is clean. I haven’t been around diesels long enough to decipher one knock versus the other or what’s normal, but it definitely makes a little more clatter than the other side.
like you, both of them run great. No smoke at start or under load, smooth acceleration, etc. CAT did replace all injector seats on the quieter side last year before I purchased the boat because they discovered combustion gas in the return line. The “loud” side was checked and passed, and the overhead was run on both engines.
keep us posted on your progress - do you have any video of the sound?
Carver370
Well-Known Member
- Mar 30, 2007
- 1,927
- Boat Info
- 2000 Sea Ray 400 Sundancer - Diesel
- Engines
- T-3116 CAT - 350 HP
I do but it’s not under normal parameters. Cat ran the overhead and tried adjusting it to make the sound go away which it actually made worse in my opinion.
I’ve sold probably 100 ish boats with 31 series Cats in them so I know how they should sound.
Not sure how I can post it here.
i usually use youtube. Here is ours from the survey but both are running and the quality isn’t great. I’ll have to get a video of each running this spring
Carver370
Well-Known Member
- Mar 30, 2007
- 1,927
- Boat Info
- 2000 Sea Ray 400 Sundancer - Diesel
- Engines
- T-3116 CAT - 350 HP
You mostly hear it in the video when putting the port engine in gear at idle. It’s a sharp noise. Idling in neutral it’s hard to decipher.
Carver370
Well-Known Member
- Mar 30, 2007
- 1,927
- Boat Info
- 2000 Sea Ray 400 Sundancer - Diesel
- Engines
- T-3116 CAT - 350 HP
i probably wouldn’t pick up on it if you didn’t point it out but I hear what you mean.
looks like that side idles higher in neutral, or is it the gauges?
Carver370
Well-Known Member
- Mar 30, 2007
- 1,927
- Boat Info
- 2000 Sea Ray 400 Sundancer - Diesel
- Engines
- T-3116 CAT - 350 HP
Yes at that point it does since Cat changed a bunch of parameters and did not set the governor correctly at all. They need to come back and fix that as well in the spring. We held off as long as we could but that video was November 5th and my marina was screaming at me to haul the boat so they could close up the building.
What do the oil analysis look like on this engine? Fuel or high carbon content? Aluminum / Chromium high?
As a LL from me I didn't know they do not analyze for fuel in oil unless specifically requested - FYI
Also, there are five little plastic check valves and screen filter in the fuel injection unit that can cause erratic engine idle behavior; they tend to gum up over time and the check valves will not seal well. Consequently rail pressure can be unstable and pulsate. Have you changed these? They are inexpensive and fairly easy to access.
gotcha, I had to give my starboard side a little more throttle to keep it in sync in gear and it turned out to be a bent strut causing serious drag on that driveline. Mine would do the same when I pulled it out of gear.
I doubt it’s your issue, that would be a heck of a coincidence, but you could easily tell by rotating the shaft by hand in neutral to see if it’s tight. I needed a wrench on the coupler bolt to get it to turn, meanwhile the other side was a one hand operation to spin it.
Carver370
Well-Known Member
- Mar 30, 2007
- 1,927
- Boat Info
- 2000 Sea Ray 400 Sundancer - Diesel
- Engines
- T-3116 CAT - 350 HP
What do the oil analysis look like on this engine? Fuel or high carbon content? Aluminum / Chromium high?
As a LL from me I didn't know they do not analyze for fuel in oil unless specifically requested - FYI
Also, there are five little plastic check valves and screen filter in the fuel injection unit that can cause erratic engine idle behavior; they tend to gum up over time and the check valves will not seal well. Consequently rail pressure can be unstable and pulsate. Have you changed these? They are inexpensive and fairly easy to access.
Those check valves have been changed as part of what they were figuring out. I totally forgot about that. The oil analysis is perfect just like the other engine. There is nothing happening internally at all. It makes 2845 rpm at wide open and doesn't smoke or burn any oil whatsoever. I have oil samples from 2005 to current with this boat and all always come back just about the same.
Cocktail Time
Well-Known Member
- Jul 9, 2007
- 1,208
- Boat Info
- 1998 400 Sundancer, Garmin 840xs GPS, Furuno Radar, B&G GPS pilot etc.
- Engines
- Cat 3116's, Westerbeke 7.6 BTD
Ok Cat experts. We serviced my boat yesterday 340hp 3116's and this is the first time I am cleaning the air filters myself. I am assuming I have Walker Air Seps and know how to clean the external element, but I came across a Walker service video that talks about changing out the internal coalescer filter cartridge every 500-750 hours. I don't ever remember the tech I used before changing these or even talking about them. Where should I order them and does anyone have the part number handy? Could be why I have soot issues? Here is link to video: https://www.soundingsonline.com/vid...rvicing-walker-airsep-air-filters?jwsource=cl
- Jun 2, 2008
- 5,023
- Boat Info
- 1998 450 Sundancer, Achilles dinghy w/15hp
- Engines
- 3126 Cat's
My '98 has the older style that doesn't have the internal coalescer filter....
- Jun 5, 2016
- 5,553
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
If you have Walker Airseps, you might have have the CAT Engine Crank Case Breather.
It looks like an upside down oil/fuel filter and is located on top of the fuel filter assembly. Here's the procedure.
There is also a smaller round air filter called the vacuum regulator. That needs to be cleaned/replaced as well.
It looks like an upside down oil/fuel filter and is located on top of the fuel filter assembly. Here's the procedure.
There is also a smaller round air filter called the vacuum regulator. That needs to be cleaned/replaced as well.
Thanks for this, I replaced the vacuum regulators when I cleaned our primary filters but never cleaned the breather. I'm also ordering those reducer hoses ours are all cracked. CAT PN 6I-2068
- Jun 5, 2016
- 5,553
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
Soot usually indicates high engine load / restricted air intake ( so make sure the air intake side is clean, unrestricted, and no leaks first).
Does your engine reach 2800 + 25-50 RPM? If not, you'll need to reduce engine load. Either less "stuff" ie fuel, people, beer (god forbid...proceed to next step) etc, or have the props reworked to a slightly lower pitch (probably what most owners do) to accommodate how you load the boat.
Does your engine reach 2800 + 25-50 RPM? If not, you'll need to reduce engine load. Either less "stuff" ie fuel, people, beer (god forbid...proceed to next step) etc, or have the props reworked to a slightly lower pitch (probably what most owners do) to accommodate how you load the boat.
Cocktail Time
Well-Known Member
- Jul 9, 2007
- 1,208
- Boat Info
- 1998 400 Sundancer, Garmin 840xs GPS, Furuno Radar, B&G GPS pilot etc.
- Engines
- Cat 3116's, Westerbeke 7.6 BTD
No problem reaching 2800+, Air sep needed cleaning but not bad, I will clean the vacuum regulator filter and breather element and see if that does it. Couldn't hurt! Thanks for clarifying.
