Official Caterpillar3116/3126 Thread

Mine are 24 years old this year, I guess they came off in 2003 when CAT warrantied the blocks. All I have done is kept the zincs fresh and Rydlimed twice...
 
As I read the survey, I see mostly normal findings, however, there is no service history available. He cannot see if the 250 hour overhead service was done or not and this one is critical. As the valves wear in, they sit lower in the head so there is a risk of the valves impacting a piston if the 250 hour valve and injector service isn't done. The injector adjustment affects the timing of the injectors so the engines will run quieter, smoother, be more efficient and smoke less if the injector timing is correct.

"Don't run the boat" is not what the Cat Technician suggested. The recommendatioin was to avoid long trips.
 
One other thing…

Resetting the head is done at 250 hours and at 2000 hrs. There is no 1000 hour service on these engines.

if there isn’t a history of this service, then you may want to have this service completed. Call you local CAT dealer and get a quote. It’s one of the few things better left t9 the CAT dealership.

Add that to the list…

I believe cat says to service the aftercoolers at 1000 hours
 
What are your thoughts on running barnacle buster thru the raw water side of the engines?
 
Alright, I warmed the motor up this afternoon at about 2 and then turned it on again at about 4:45pm and let it warm up to 180 degrees per the engine gauge before testing and before dialing up RPMS.

Temp Gun Results:
(IN NEUTRAL AT DOCK)

750+/- RPMS
Engine Temp Gauge Reading 180 degrees
Bridge Temp Gauge Reading 175
HEX : 81.5
Expansion Tank: 156
Regulator Housing: 172
Gear Cooler: 86
After Cooler: 79
Block: 163
Oil Filter: 163.6

1200+/- RPMS
Engine Temp Gauge Reading 195-199
Bridge Temp Gauge Reading 190
HEX: 126
Expansion Tank: 178
Regulator Housing: 195
Gear Cooler: 99
After Cooler: 80
Block: 175
Oil Filter: 173


....I have a NEW 190 degree Thermostat in the Regulator.
Waiting on some more testing supplies to show up to check other things.
 
Alright, I warmed the motor up this afternoon at about 2 and then turned it on again at about 4:45pm and let it warm up to 180 degrees per the engine gauge before testing and before dialing up RPMS.

Temp Gun Results:
(IN NEUTRAL AT DOCK)

750+/- RPMS
Engine Temp Gauge Reading 180 degrees
Bridge Temp Gauge Reading 175
HEX : 81.5
Expansion Tank: 156
Regulator Housing: 172
Gear Cooler: 86
After Cooler: 79
Block: 163
Oil Filter: 163.6

1200+/- RPMS
Engine Temp Gauge Reading 195-199
Bridge Temp Gauge Reading 190
HEX: 126
Expansion Tank: 178
Regulator Housing: 195
Gear Cooler: 99
After Cooler: 80
Block: 175
Oil Filter: 173


....I have a NEW 190 degree Thermostat in the Regulator.
Waiting on some more testing supplies to show up to check other things.

Double check your thermostat, I believe the new one is 195°. I replaced mine 3 years ago.
 
Double check your thermostat, I believe the new one is 195°. I replaced mine 3 years ago.

I have an extra one that i bought to replace my port side, it says 190 degree? Though i would prefer to have the old 185 degree back.

Edit: Also, Caterpillar lists 2 options on the parts page. I is $15, the other is over $70. Anyone know the difference?
 
Alright, I warmed the motor up this afternoon at about 2 and then turned it on again at about 4:45pm and let it warm up to 180 degrees per the engine gauge before testing and before dialing up RPMS.

Temp Gun Results:
(IN NEUTRAL AT DOCK)

750+/- RPMS
Engine Temp Gauge Reading 180 degrees
Bridge Temp Gauge Reading 175
HEX : 81.5
Expansion Tank: 156
Regulator Housing: 172
Gear Cooler: 86
After Cooler: 79
Block: 163
Oil Filter: 163.6

1200+/- RPMS
Engine Temp Gauge Reading 195-199
Bridge Temp Gauge Reading 190
HEX: 126
Expansion Tank: 178
Regulator Housing: 195
Gear Cooler: 99
After Cooler: 80
Block: 175
Oil Filter: 173


....I have a NEW 190 degree Thermostat in the Regulator.
Waiting on some more testing supplies to show up to check other things.

=========

I think the key here is to COMPARE the readings at various locations from port to starboard on both engines to discover where the hot points occur.

RWS
 
Getting back to after cooler. ...would be nice if we had independent threads....
I believe there may be two problems with barnacle buster. It may be too caustic on a part no longer available. More importantly it omits pressure testing unless that could still be done while installed.
 
Getting back to after cooler. ...would be nice if we had independent threads....
I believe there may be two problems with barnacle buster. It may be too caustic on a part no longer available. More importantly it omits pressure testing unless that could still be done while installed.

Can still use Etch and Prep.
 
I believe cat says to service the aftercoolers at 1000 hours

You are correct. I guess I should be a little more specific. I was referring to resetting the Valve Lash and Injector Timing as this is about the only thing that is a little more than a DIY job, primarily because CAT has some special tools to accomplish the job. Valve Lash is at 250 hours, then again at 2000. Injectors timing is at 2000 Hrs.

Cleaning the aftercooler and changing the ELC along with about everything else on the list are easily DIY jobs for most of us. The "1000 hour" service, has three ways to measure, 8000 gallons of fuel burned, 1000 hrs or 2 years. I would bet almost all of us will get to the 2 years before we hit the 1000 hours or 8000 gallons of fuel.
 
Last edited:
I got lucky, without asking my girlfriend's brother-in-law, who works for caterpillar, now in sales but used to be a mechanic, volunteered to help me do all the service on this boat if I get it. Needless to say I'm excited about that because I can learn how to do it myself from a caterpillar mechanic.

He said all of it's pretty straightforward and easy to do, including the injectors and valves. The only caveat is he's never worked on Marine engines, only heavy equipment so the raw water side of things will be new to him. He knows the 3126 very well.

Caterpillar came back with a $20,000 estimate to do both main engines.
 
I got lucky, without asking my girlfriend's brother-in-law, who works for caterpillar, now in sales but used to be a mechanic, volunteered to help me do all the service on this boat if I get it. Needless to say I'm excited about that because I can learn how to do it myself from a caterpillar mechanic.

He said all of it's pretty straightforward and easy to do, including the injectors and valves. The only caveat is he's never worked on Marine engines, only heavy equipment so the raw water side of things will be new to him. He knows the 3126 very well.

Caterpillar came back with a $20,000 estimate to do both main engines.

you might owe that man a drink
 

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