The CAT 3126 is a very sophisticated engine with high torque, power, and displacement. It is an upgraded version of 3116. It is regarded as a reliable and durable engine because of its look-alike design with 3116.
Its ability to work on different applications, such as school buses, industry equipment, and agricultural equipment, makes it popular.
As usually said, no engine is immune to fault and breakdown; therefore, let’s consider the common problems found in the CAT 3126.
1. Injector synchronization: This is the most difficult aspect of this engine. This occurs when you replace the injectors or repair the injectors, and you need to synchronize the injectors. The Injectors must be synchronized; the synchronization requires a special tool like a dial gauge to have accurate adjustment.
If any of the injectors are offset, the engine could be knocking, misfiring, or runaway.
Unlike some engines, installing the injectors does not require a special tool or setting.
2. Troubleshooting issues: CAT diagnostic computer
This is another issue with this engine. The engine is electronic, which means you would need some special tools to troubleshoot it. For example, with some error code problems, you would have to consult the CAT diagnostic computer to fix the error problem. The engine cannot be regarded as a simple engine to fix.
Due to the electronic nature of the engine, the diagnostic computer is sometimes needed to carry out the troubleshooting so that an error or fault can be fixed.
3. Engine derate: Engine derate simply means when the engine power or the output becomes lower than usual in an abnormal way. It is another condition that you could face in this engine.
What could be the problem? In the CAT 3126, the problem can be caused by a low coolant level, or it could be due to a high-temperature coolant. Another reason could be low oil pressure.
There is a sensor that monitors the coolant level at the upper part of the radiator. If you could get the code, then you can check the cause.
4. Limp mode: Limb mode is a signal you receive when there is a fault in the engine or transmission, and the limb mode turns off certain functions. You will be left with only essential functions.
For example, in 3126, this error code 164-11 is one of the most frequent error codes you could experience. This code usually comes up due to injection Actuation Pressure System fault. Which simply means that the ECU is not receiving the info from the injection Actuation Pressure.
The cause could mostly be faulty Injection Actuation Pressure Control valves.
You should also remember that a faulty IAP sensor could be another reason for the limp mode on this engine.
Another vital point to add is fuel leaks from the injectors. These are the reasons for such limb mode and error code on the 3126 engine.
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5. HEUI PUMP Issues: This is one of the major problems of this engine. This pump is prone to failure. It is one of the headaches you will encounter on this engine.
Sometimes, some particles could go from the pump to the injectors, which could cause problems for the injectors; it is on this note that some have decided to install a fuel filter in between the pump and injectors.
6. Low oil pressure: The engine also has low oil pressure issues.
When facing such a problem, you need to check the oil pump pressure. You can do that by using the manual gauge to know the oil pressure.
Do not forget that bad crankshaft bearings could be the reason for low oil pressure. You need to check if it’s still in good condition.
7. Shutdown Solenoid: This is the solenoid that helps to shut down the engine whenever you want to shut down the engine. But when the shutdown solenoid is bad, it malfunctions and shuts down the engine even when the engine is running.
What you can do is bypass the solenoid and run the engine. If the engine runs without the solenoid, then you know you need to replace the solenoid
