Official Caterpillar3116/3126 Thread

Thank you. Will try. On another note. This engine idles at 740 ish. When push in fwd or reverse it slows down about 100 to 150 RPMs (to 600 give or take). Then comes back up in neutral.
Any ideas

we drop about 100 rpms in gear as well, seems normal
 
we drop about 100 rpms in gear as well, seems normal

I would agree I see about 100 RPM drop. My port really needs an adjustment as it drops below 600 in gear and I have to manual adjust up.

Here's is the procedure that Dave from Boatdiesel.com suggested multiple time over the years.

I'm not this Dave by the way...

upload_2023-5-25_21-1-52.png
 
I would agree I see about 100 RPM drop. My port really needs an adjustment as it drops below 600 in gear and I have to manual adjust up.

Here's is the procedure that Dave from Boatdiesel.com suggested multiple time over the years.

I'm not this Dave by the way...

View attachment 145039

yup, works perfect. The key is to be fully warmed up, like go for a decent ride and adjust out on the water, run again, check idle. I find if I mess with it in the slip after the engine has had any chance to cool down it’s off the next time I run the boat.
 
It took me quite some time to get mine the way I want it. That little screw is the buffer screw and actually does make a big difference by adjusting it in super small increments.

I finally have mine almost dead on together when in gear at idle. It drove me insane watching the digital tachs off from each other.

A good tip that a few Cat guys have shown me, when you have the idle set the way you want it, manually rev up the engine a little a few time and let it settle down at idle, adjust as needed and then reconnect the linkage.
 
My port also drops below 600. It never use to. Not fun around the docks. If I bump it up with the control I have to remember to move the lever back down or the the rpms will be high when I shift into fwd. my stbd only drops down to about 690.
 
Hey everyone, I am wanting to do my impellers this year, and started looking at replacing my port side engine in my 400 DA (easy side LOL). The fuel cooler line is really in a bad spot, it has an elbow that allows me to rotate it side to side, but I still can't seem to get the required clearance needed. I read that some owners have put on a different elbow to facilitate the impeller removal, has anyone here done this and have a pic?
 
Hey everyone, I am wanting to do my impellers this year, and started looking at replacing my port side engine in my 400 DA (easy side LOL). The fuel cooler line is really in a bad spot, it has an elbow that allows me to rotate it side to side, but I still can't seem to get the required clearance needed. I read that some owners have put on a different elbow to facilitate the impeller removal, has anyone here done this and have a pic?
Sometimes its easier (especially the first time or two) to remove the entire water pump off the engine and replace the impeller on the bench. Bonus on a new to you engine is you can get a look at the condition of the pump and insure the seals and wear plates are in good condition.

Short of that, I think sometimes, various fuel, and or oil lines might need to me moved/loosened, but usually once you know how it goes, it can be done on engine.
 
Hey everyone, I am wanting to do my impellers this year, and started looking at replacing my port side engine in my 400 DA (easy side LOL). The fuel cooler line is really in a bad spot, it has an elbow that allows me to rotate it side to side, but I still can't seem to get the required clearance needed. I read that some owners have put on a different elbow to facilitate the impeller removal, has anyone here done this and have a pic?

I have same boat, same engines. The fuel line in front of the impeller is part of the return system so no worries to disconnect it (3/4 inch wrench if I recall) while working on the impeller. I put an absorbent pad underneath it, remove it from the cooler and then place it up high, it's flexible line and that clears the way.

Same on the starboard side, except I remove the exhaust tube 1st.

Also, if your impeller housing cover plate is scored, do yourself a favor and replace it straight away. I learned the hard way this year.

Also, don't forget to replace the o ring.
 
Thanks so much everyone, I didn't realize that fuel line was just a return. Nervous about opening things up with the mechanical injection. I will remove it and the oil sensor and then it should be easy peasy. I have the backing plates coming in and I will replace both and new o rings.
 
Thanks so much everyone, I didn't realize that fuel line was just a return. Nervous about opening things up with the mechanical injection. I will remove it and the oil sensor and then it should be easy peasy. I have the backing plates coming in and I will replace both and new o rings.
You can slide the fuel cooler back (towards rear of engine) about 1/4 inch and flip that fitting and hose around to the other side of the oil pressure sender. Then it is out of the way for good.
 
Thanks for the info. Oil analysis is done annually with the winter layup oil change. Last analysis was this past October (results showed no issues). First time starting her up since then was last week and that's when the knock started. Tech took oil samples, but likelihood of finding anything is slim as the engine was only run for five minutes since last October's oil change. Went from travel lift to slip. Haven't run her since for fear of damaging the engine. Figured I'd wait till CAT looks her over.

As for the check valves, haven't changed them. Quite honestly, wouldn't even know where to look up the parts..

did you ever get another diagnosis on your issue? Curious how you made out
 
I’m looking to install egt probes. Will someone please tell me what the type and size thread is?
 
I’m looking to install egt probes. Will someone please tell me what the type and size thread is?

here is everything I bought from ISSpro to get EGT and boost in a combo gauge. I did not require any other parts on the egt size, the kit was complete. Hope this helps
IMG_0808.jpeg
 
did you ever get another diagnosis on your issue? Curious how you made out

My apologies for the delay, work has been kicking my ass lately... Foley CAT got to it last week. He pulled all the injectors and inspected the cups and found some rust in all six cups, two of them has quite a bit of rust on them. He reamed all the cups to clean them up. He then ran the numbers on testing and rebuilding all the injectors and the cost, given the man hours needed at CAT's hourly rate (Big $$$$), was comparable to just replacing all six injectors.. Decision was made to replace all the injectors. Thankfully, he thought ahead given the supply issues CAT has been having and ordered them when he first looked at the engine three+ ago so they were available immediately.

She now purrs like a kitten.
 
My apologies for the delay, work has been kicking my ass lately... Foley CAT got to it last week. He pulled all the injectors and inspected the cups and found some rust in all six cups, two of them has quite a bit of rust on them. He reamed all the cups to clean them up. He then ran the numbers on testing and rebuilding all the injectors and the cost, given the man hours needed at CAT's hourly rate (Big $$$$), was comparable to just replacing all six injectors.. Decision was made to replace all the injectors. Thankfully, he thought ahead given the supply issues CAT has been having and ordered them when he first looked at the engine three+ ago so they were available immediately.

She now purrs like a kitten.

awesome!! You made the same decision we did, I couldn’t bear tearing down the overhead and putting the old injectors back in, good or not.

did you get the remans or new injectors?
 
awesome!! You made the same decision we did, I couldn’t bear tearing down the overhead and putting the old injectors back in, good or not.

did you get the remans or new injectors?

went with new injectors. Given CAT's hourly rate, which includes travel to/from the boat, decided to get new so they would be covered under warranty...
 

Forum statistics

Threads
111,814
Messages
1,393,703
Members
60,196
Latest member
twerth
Back
Top