6 Common John Deere 6068 Engine Problems (And Solutions)

The purpose of an engine is to provide power that is controlled by the transmission system. The engine requires integrity of the mechanical system for efficient operation. John Deere 6068 refers to an engine configuration of six cylinders, operating on a four stroke cycle. It is regarded a marine engine due to its design intent for heavy duty applications. The engine encounters various problems as discussed later in this article. Various trouble shooting guides are provided in manuals and the internet to address them.

Engine problems with John Deere 6068 vary from hard starting, loss of engine power, engine stalling, overheating and abnormal engine noise. Some of these problems have some guiding tips for troubleshooting within the manual provided by the supplier. It is therefore a recommended practice to follow the guidelines as the primary trouble shooting guide for these problems.

Table of Contents

1. Engine Does Not Start or Starts Hard

When John Deere 6068 engine encounters starting problem, below are the things to look into:

  • Blocked fuel filter. The purpose of the fuel filter is to clean the fuel of all the debris that may have contaminated the fuel. As time goes on this unit gets clogged or blocked by these dirt particles and they lose efficiency. The movement of fuel is limited to the engine for ignition during the combustion stage. As a result the engine may take long to start also known as hard staring. In worst cases the engine may not start at all. To resolve this problem, remove the fuel filter and clean it. Replace it and test the engine. If the problem persists, replace the filter with a new one.
  • The other root cause of the starting problem is air in the fuel system. Air usually is introduced when tank runs out of fuel. As you refuel fuel lines will be having air which affects engine starting performance. To get rid of this root cause, it is recommended to perform fuel system bleeding. This method implies pumping fuel out through all pressure lines until no more bubbling is observed through all the pressure lines. This way all the air has been removed and try starting the engine again.
  • Thirdly, clogged or burnt injection nozzles are known to cause engine starting problems and the most recommended practice is replacement using a new kit.
  • In case of a damaged fuel injection pump, follow John Deere 6068 engine procedure for pump replacement with a new one. Sometimes consult specialist to attend to the faulty pump and test reconnect and test its performance.

2. Sudden Engine Stop During Operation

John Deere 6068 engines also face challenges of suddenly stopping during operation and some causes are highlighted below.

  • Incorrect fuel injection pump timing. Fuel injection into the combustion chamber should be correctly timed for combustion to begin and allow engine to continuously run without stopping. If the timing is incorrect or lost, the John Deere 6068 encounters operation problems and stops suddenly during operation. To attend to this problem, it is recommended to follow John Deere 6068 manual provided by supplier to correct the timing or contact technical personnel to assist.
  • Clogged fuel filter is also known to cause engines to stop suddenly during operation. It is also advised to check and resolve clogged fuel filter as discussed above.
  • Lastly, it is important to ensure your engine is warmed up. This ensures that recommended operating temperatures for the fuel vaporization has been reached for efficient operation. Using John Deere 6068 manual procedures, perform engine warm up process to avoid engine sudden stops during operation.

3. Engine Stalling

This refers to engine sudden stopping after starting. As discussed above, the following are known causes for that.

  • Clogged air and fuel filters are known to be the major causes. To solve the problem, cleaning the filters and or replacement with new units will address the problem.
  • Damaged fuel injection system is also another cause for stalling in John Deere 6068 engine. Contact an authorized person to repair or replace the faulty injection system.

4. Engine overheated

For all engines to work efficiently and deliver power continuously, they operate within set temperature limits. If engine temperature gets too hot, the engine performance is compromised. The causes of engine over heating vary but generally all are related to cooling system failure.

  • Dirty, damaged or faulty radiator core. These are known to be among the top causes for engine overheating. Dirt radiators requires cleaning or replacing with new caps.
  • Low coolant levels also causes engine overheating. Always check and ensure engine is within the correct level limits. Make sure to top up low oil with John Deere 6068 recommended engine oil grade.
  • Defective fan belt or lose belt causes engine overheating. Recommended practice is replacement of faulty belt or tensioning of loose belt to ensure engine operates within design temperatures while delivering top performance.
  • Lastly, low crankcase oil levels causes engine overheating. Always ensure the oil levels are maintained within defined oil level limits. When topping up, always top up with recommended grades and oil types to solve engine overheating problem.

5. Abnormal Engine Knocking or Noise

  • Operating the engine at low temperatures results in low coolant temperatures which makes the coolant ineffective. To bring up the coolant to required temperatures, warm up the engine as discussed above,
  • Abnormal engine knocking of John Deere 6068 is caused by worn out pistons which can be solved by replacement. Additionally if the connecting rod is defective abnormal sounds are observed. Replacement or realignment of connecting rod resolves the problem.
  • The other known causes of abnormal knocking sound are low engine oil and lost fuel injection pump timing. Steps to resolve these have already been discussed above. For additional steps or procedures for attending to these problems, the manual is a very effective tool.
  • Crank shafts have end play which if becomes excessive will result in abnormal engine knocking sound. If this is the case, contact the authorized John Deere 6068 dealer to assist resolving the problem.
  • Worn out rocker arm shafts and camshaft lobes are also responsible for abnormal engine sound. Only competent personnel are authorized to repair or replace worn out camshaft lobes and rocker arm shafts.

6. Engine Cranks slowly

This problem in John Deere 6068 engines is caused by either low battery voltage, or crank case oil that is too heavy. To solve this problem use recommended oil viscosity and replace or recharge faulty battery.