Saturday, October 10, 2009

Cat 3116 Diesel Engines

I've been getting a lot of questions on 3116 Cat Diesel Engine problems. The one stumbling block is the tooling you need to repair these model engines. After the basics like fuel supply and electrical issues are taken care of the next step is replacing injectors and other related tasks.

The tools required for tuning up these engines come in a kit and costs over $2000.00 in my part of the world. These tools must be used to get this engine synchronized, timed and set up properly.

If you have access to the tools that's great, a manual accompanies the kit. There is a learning curve with setting up the 3116 but do it once and you'll understand the concepts behind the injection system.


There are glitches with the 3116 are usually the same and I have posted them as they happened on this blog. The exhaust valves are weak and it seems like #5 exhaust valve is a weak spot. Keeping the valves set is a good practice and prevents a tight valve and overheating.

If you use the search box above you can get more details on tune ups and repairs. There are specific rebuild procedures covered as well.

Or you can check all the posts out here:

http://schoolbusmechanic.blogspot.com/search?q=cat+3116

You might have to be more specific with your search i.e "cat 3116 oil pump"

You can always make a comment or ask a question and I will get back to you...

14 comments:

Cummins24v2001 said...

John, I am interested in obtaining a bit more power out of my model year 1997 CAT 3116 175 hp motor, I have seen articles informing me to turn up the fuel by adjusting the fuel screw located between the # 1& #2 rocker arms, do you have pictures of this fuel screw and brief instructions? I have taken the truck to 3 repair shops that claim to know CAT motors and 2 of the 3 swore my motor was computer controlled and fuel could not be adjusted. After hearing this, I told them to go back to school and headed to the next repair center. any help on fuel and timing adjustment would be greatly appreciated. Scott Grasmick email Scott@bayshorehardscaping.com

John said...

Do a search for "Cat 3116 fuel setting" and you will see how it's done with the Cat tools(which you need).Your engine would have to be a 3126 Model to be Electronic.

School Transportation News Blogs said...

Hi John, can't find any contact info for you but would like to talk regarding the STN EXPO 2010...www.schoolbusconference.com. Look me up, I'm Ryan, at www.stnonline.com. You talked I think before with my former assistant editor David Wegbreit.

Thanks.

Anonymous said...

hi john i have a 1997 chev 6500 with a3116 i recentley had an injector on#3 replaced the mechanic that replaced it also adjusted the rack now the engine is very noisey (sounds like loose rocker) he claims #3 cycl. would adjust and sound good for a few minutes then go back to being noisey my question is could this be a cam or lifter problem or a worped rocker assembly im green on these engines thanks s k

John Whelan said...

The noise could be from the replaced injector. If you remove the rocker cover you can run the engine and disable each injector one at a time by running your finger down the back of the injector body and pushing the rack pin towards the main rack. What this does is put the injector into a full fuel mode and this will help you determine if there is an engine miss and which cylinder it's coming from.

Tractor Mom said...

lot of time if the injector still has o ring on it will cause a fuel knock just do away with o ring i used to this when work for cat dealer

J. E. Whelan said...

The injector body has a specially machined body that fits into the seat in the injector bore using the hold down tool. If the injector does not seat you will get air in the fuel system.

Cindy said...

Hi John..I have a Cat 3116 Diesel Engine in my School Bus and was wondering if a 3208 Diesel Engine would fit in and work with a automatic transmission?

Cindy said...

Hi John..I have a Cat 3116 Diesel Engine in my School Bus and was wondering if a 3208 Diesel Engine would fit in and work with a automatic transmission?

Transporter11 said...

Hello John. God has blessed our camp with a 1995 Thomas Built school bus with a 3116 Cat Engine. The engine has two issues that concern me. The first is that the engine surges at all speeds. The second is that the engine will shut off after driving at highway speeds for 15 or more miles. So far it has always restarted, but I'm fearful that may not always happen. Our mechanic told me the fuel pump is getting ready to die. Could it be something else that maybe isn't so expensive to fix?

J. E. Whelan said...

Check the fuel shutdown solenoid at the Governor. It has 2 wires to it and they run hot. It's possible it may be faulty or you have a governor problem causing the surging.

Anonymous said...

i got a cat 3116 that drops fuel pressure when it feels like it. rebuilt transferpump,, blowout lines replaced filter housing on engine and by passed the one belowdrove it 40 miles fine. left mech house got 10 miles and it died again. took 15 min to get it to run and took it back parts and labor 1000.00 Help???

Bubba said...

I have a 3116 cat and it has fuel coming out the exhaust .

DieselStudentinOK said...

John, first off, thank you for such an awesome helpfull blog for new technitions like myself! At school we are working on a '94 GMC Topkick with a 3116 in it. It has had some of the fuel lines from the tank to the primary filter replaced, the pump/governor unit replaced, and it only has about 20k miles on it. It ran fine for my instructor on about a 25 mile drive home after we did said work to it. He let it sit about 4hours, then when he went to deliver it, it drove about 500 feet and went back to having near zero power. It won't hardly pull itself over a bump in the road when it does this. Could it be the injectors leaking compression like I read in another of your posts? Thanks again for sharing your experiance with us!