John Deere 4240 Problems (Troubleshooting Guide)

The engine making strange noises or not starting is always a concern for any vehicle owner. The underlying problem can be tiny or large, depending on the situation.

Although John Deere tractors have superb all-around performance, it occasionally has engine or steering problems.

John Deere 4240 can face several hydraulic, steering, and electrical problems as it is dependent on mechanical and electrical components. Broken fuel system parts cause most of these issues. There are, however, other probable reasons. Thankfully most of these issues get fixed by replacing the faulty components or by simply cleaning them. 

The first step in solving these issues is to recognize them. We have written this guideline to address all potential issues and provide frequent maintenance advice.

John Deere 4240 Engine Problems

Problems Reasons Solutions
Engine Doesn’t Start Clogged Fuel filter plugging & No fuel supply

Air leak from Fuel lines

Clogged or damaged injectors, fuel injection pump

Replace fuel filter 

Check & reopen fuel supply valve

Replace faulty pipes & injectors

Engine Abruptly Stops After Starting Incorrect fuel injection pump timing

Dirty fuel filter & air cleaner

Faulty injector nozzle & fuel injection pump 

Adjust fuel injection timing

Clean and reinstall the fuel filter & air cleaner

Test and replace.

Engine Stalls at idle Incorrect low idle setting 

Faulty fuel injection pump 

Inaccurate valve clearance 

Adjust the correct idle setting

Test  fuel injection pump/replace

Adjust the valve clearance

Engine Overheating Low coolant &  engine oil level 

 Faulty Cooling system  

Inaccurate Thermostat

Refill the oil and coolant

Test the cooling system /replace

Adjust the thermostat

Engine Power Loss Dirty injectors, air filters, oil filter

Incorrect Fuel injection pressure 

Overloaded Engine 

Clogged fuel hoses 

Clean / replace these parts

Adjust the pressure to recommended

Decrease the load

Clean fuel system

Noisy Engine Insufficient oil, Crankshaft failure

Loose flywheel screws

Refill the tank, replace the faulty parts

Tighten loose screws

Engine using too much oil  Oil leaking, inaccurate oil viscosity

Stuck piston rings

Scuffed cylinder liners

Change defective parts, use correct oil

Replace piston rings

Inspect liners & replace to solve the John Deere 4240 Engine Problems.

Problem 1: Engine Doesn’t Start

Not being able to start your engine at all is one of the worst engine issues. The fuel system is frequently the source of the problem. However, there are a few additional factors that could be at play.


Filters, injectors, or fuel shut-off valves that are dirty can easily prevent the engine from starting. Sometimes, the shut-off valve may be shut, making it impossible to start the engine.

Low compression occasionally prevents the engine from starting due to a faulty fuel injection pump.

Additionally, the air is commonly caught in the fuel system, which prevents the engine from starting. Engine having low compression can also stop the engine from starting.


To find out which case is hurting your engine, it is best to examine each separately. Remove the old fuel filter and replace it with a new one.

If the shut-off valve is closed, take it out of the compartment and check to see what is causing it to do so. If not, put it back in and keep it open.

The broken injection pump should be replaced with a new one. This will also fix the low compression issue. But to stop air from entering the system, you should also examine the cylinder block and replace any defective parts.

Problem 2:  Engine Abruptly Stops After Starting

The cause of an unexpected engine shutdown can occasionally be something minor. Even a minor issue, like a cold engine, can cause problems. However, the fuel system could also be to blame.


Sometimes, the engine is not warm enough to work and stops abruptly due to cold weather. It may be crammed with mud, liquid, or even air. Incorrect fuel injectors may occasionally be at blame for this. 

Moreover, fuel injection that is placed incorrectly can cause the engine to shut off.


You can start the engine and let it run for a few seconds before driving if the engine isn’t warm enough to run smoothly.

However, be cautious and park it securely before starting the engine. Start slowly for the first 10 minutes as you remove it.

Check the injectors and fuel filters for the fuel system issue. Remove the injector and give it a thorough cleaning if there is dirt or debris trapped in the fuel system.

However, purchase a new fuel filter if any components are broken or damaged.

Problem 3: Engine Stalls at Idle

Your engine will run more smoothly and can continue powering the power steering or alternator if you keep it idle. However, the engine sometimes unexpectedly stops when idling.


There are four potential reasons why an engine might abruptly shut off while idling. Two of them are fuel-related. Maintaining idle becomes challenging when fuel injection pumps are faulty or malfunctioning.

Additionally, the fuel injector nozzles clog over time, preventing the engine from receiving enough fuel to maintain idle.

Occasionally, the engine will shut off because the low idle speed settings are incorrect. Improperly adjusted valve clearance can result in a complete engine shutdown.


Fortunately, there is an easy solution to this issue. The carburetor’s idle speed adjustment is simple. The primary throttle linkage on the driver’s side needs to have its screw adjusted.

By tightening the screws, the valve clearance can be conveniently changed. It usually moves a few inches, and putting it back in place fixes the problem. However, it is preferable to visit a technician and have it corrected.

If the fuel injector nozzle needs to be cleaned, remove it from the injector, clean it, and re-install it. However, if it is broken, get a new one. It is preferable also to replace the damaged fuel injector pump.

Problem 4: Engine Overheating

One of the most serious problems a truck could have is an overheated engine. Warping and cracking brought on by an overheated engine can result in long-term harm.


Usually, a lack of engine coolant causes an overheated engine. However, the cooling system’s components become worn down or clogged over time, contributing to engine overheating. 

A faulty belt may also be the reason for this if the engine oil level is too low and the fan belt tension is off.


The cooling system components must first be inspected to see if any are broken. Change the belt or tighten it if it appears too loose. Replace any other broken components with new ones if necessary.

You can add more engine coolant if it becomes low, but make sure the cooling system isn’t cracked. Because that could cause the coolant to start draining in the first place.

Problem 5: Engine Power Loss

Along with the engine failing to start or overheating, it can occasionally lose power completely. There are typically four primary causes.


The primary causes of this issue are faulty fuel injectors and insufficient fuel injection pressure.

In addition to them, the air filter is filthy, and particles can easily cause this problem. Due to heavy use on the field, even the engine oil filter becomes clogged.


You must thoroughly examine each of these compartments to restart the engine. It’s better to inspect extensively because one or two might be at fault.

Check both filters and the fuel injectors first. Check to see if anything is harmed. If so, swap them out for new ones.

Replace any blocked filters with fresh ones. The fuel pressure setting can be adjusted in accordance with the suggested value from the manual or any automobile professional.

Problem 6: Noisy Engine

Noisy engines are not only bothersome but also a potentially dangerous concern. Even though there is a high likelihood that one or more parts broken are behind this, other factors could also be at play.


Along with damaged piston rings, the fuel injector nozzles get broken over time and become faulty. Moreover, crankshafts or the main bearings also fail and make a loud knocking sound.

Insufficient oil, wrong fuel injection pump timing, and loose flywheel screws also cause this problem. Sometimes, when the engine is not warmed up, it can make this noise as well.


Damaged parts need to be replaced as soon as possible, but some parts may need just tightening in their places. For faulty bearings, replacement is also the best choice. 

You can easily warm up the engine by turning it on and keeping it on for a few minutes. While refilling the engine oil, ensure there’s no contamination, and then top it off with standard-grade engine oil.

Problem 7: Engine Using too Much Oil

Tractors can consume all of the fuel even if the tank was only recently filled. This usually occurs when there is a large leak in the oil compartment or when any other system component is damaged. 

It’s not just expensive; it can also result in several other problems, which makes it worrying.


When an engine uses excessive amounts of oil, the seals or the gaskets are either broken or damaged. However, the oil viscosity is occasionally incorrect, and the engine consumes too much of it. 

At the same time, the piston ring may be fractured, and the cylinder liners may cause excessive oil use.


After a preliminary inspection, damaged components like gaskets or seals should be replaced. Cylinder liners and piston rings are available in hardware stores and online. 

However, you should speak with a professional and replace the oil as necessary to ensure the proper oil viscosity.

John Deere 4240 Electrical System Problems

Problems Reasons Solutions
Non-Charging Battery Defective battery cell, wiring harness, belt tension.

Corrosion on battery terminals or cables.

Replace battery cell, and wiring harness, adjust belt tension.

Check the cables & terminals & clean them.

Slow turn of Starter Motor Low Battery, Defective wire harness.

Loose cables and terminals.

Charge the battery or replace the battery, Check the wire harness.

Tighten the cables & terminals to solve Electrical System Problems.

Problem 1: Non-Charging Battery

The battery is the most important component for any tractor to function properly. It must be fully charged to get the electrical system up and running.

However, your battery will frequently encounter several problems that stop it from charging. 


A bad cell in the battery is the main reason for the battery not charging at all. At the same time, the wiring harness can also cause this. A faulty wiring harness can result in the tractor’s lighting system malfunctioning.

This may also be caused by corrosion on the cables and battery terminals. Sometimes incorrect belt tension or a worn-out belt can easily create this problem.


You need to replace the battery if you have a bad cell. But a wire harness can be repaired. However, sometimes it is tucked away and difficult to access. So, it is best to take it to a technician.

Corroded terminals and cables should be cleaned and tightened to their original positions.  But it’s best to opt for a new belt regarding the worn-out belt problem. 

To adjust the belt tension, you need to loosen the left adjustment nut counterclockwise while rotating your pedal.  This might also require some precision, so it’s best to take help from an expert.

Because if the belts are not properly adjusted, it can create extra load on pulleys, bearings, and shafts. 

Problem 2: Slow or No Turn of Starter Motor

The starter motor cranks up the engine during ignition and helps it operate on its own power. If the starter motor breaks down, the entire system could fail. There are several reasons for the starter motor not working properly. 


Low battery power makes it impossible for the starter motor to work.  Along with a low battery, the wire harness can also malfunction.

Moreover, the loose cables cannot connect the terminals properly, which hampers the motor’s starting.


Low-powered batteries should be charged as soon as they are detected. But sometimes, it might need to be replaced. Whether or not the wire harness needs to be replaced depends on the damage.

If the damage appears to be minor, try to repair it yourself because hiring a technician could cost you nearly $100. To rule out any loose connections, the terminals should be properly tightened. 

John Deere 4240 Hydraulic Problems

Problems Reasons Solution
Hydraulic System Overheating Improper hydraulic system pressure setting 

Defective Main relief valve 

 Dirty hydraulic oil

 Air enters the hydraulic system 

Adjust the pressure

Change the relief valve

Drain & refill with fresh oil

Check for leakage spots and repair/replace

Low Hydraulic Oil Pressure  Low Hydraulic fluid level 

Clogged Hydraulic fluid filter

Defective hydraulic spool valve

Malfunctioning hydraulic cylinder

Hydraulic lines leak

Refill the fluids

Clean the filter

Adjust the valve

Check for damage and replace

Check for leaks and repair

Hitch Problems Insufficient Hydraulic oil 

Cold hydraulic oil in system 

Defective hydraulic oil pump 

Faulty Hydraulic control valve  & cylinder

Damaged Suction line 

Worn-out arm shaft

Mechanical malfunction

Contaminated hydraulic oil 

Refill the oil

Wait for the oil to warm up

Check and replace the pump

Replace the control valve & cylinder

Check the pipeline and repair

Replace the shaft

Check and repair the component of the system

Drain & refill with fresh oil to solve the John Deere 4240 Hydraulic Problems 

Problem 1: Hydraulic System Overheating

Overheating in any part of a vehicle is a serious problem. If the temperature rises too high, it is very easy for hydraulic pumps to fail and potentially damage the whole system.


Inaccurate hydraulic system pressure can easily overheat the system. In addition, the failure of the main relief valve or incorrect valve settings can cause the engine to overheat.

The hydraulic oil can occasionally become contaminated by air in the hydraulic system. This causes the system to burn more oil to achieve a similar amount of pressure, causing the system to overheat.


You can adjust the hydraulic system pressure by adding hydraulic fluid. You can also adjust the pressure by increasing the motor speed. For a relief valve problem, you need to replace it with a new one.

If you notice hydraulic oil contamination, you need to drain the whole compartment and then refill it with fresh oil.

To inspect an air leak, you need to check the suction pipe, fittings, and pump seals. If any of them is damaged, you need to replace them as soon as possible.

Problem 2: Low Hydraulic Oil Pressure

Along with overheating systems, low oil pressure is the most common hydraulic problem when operating a tractor.

You need to have the right grade hydraulic fluid and a properly working system to get proper hydraulic oil pressure. 


Hydraulic pump failure mainly causes this issue. But a low fluid level with a clogged filter worsens the low-pressure issue. Moreover, the spool valve block gets worn out over time.

The hydraulic cylinder also tends to malfunction, making the pressure get low than it should be. And with time passing, you can expect to have leakage hydraulic lines.


Any of the given reasons could be behind this, so you need to check all of these possible causes. Refilling the hydraulic fluid will increase the pressure a great deal. But the clogged filter & pump needs to be replaced. 

The defective spool valve should also be replaced, but if it seems damaged-free, you can solve the issue by readjusting it to its proper position.

For cylinder malfunctions and leaks in hydraulic lines, you must check thoroughly and replace the damaged part.

Problem 3: Hitch Problems

Three separate arms are used to make a three-point hitch, and each arm has a very specific purpose. The hitch itself won’t move as easily or smoothly as you may think if one of them begins to malfunction.

A 3-point Hitch can start to malfunction if the reasons behind low-pressure oil start showing. But along with those reasons, a couple of other things might cause this issue.


A few different things can occasionally cause the hitch issue. But most of the time, it is hydraulic fluid. Sometimes there isn’t enough hydraulic fluid, and other times there is enough fluid, but it’s too cold due to the weather.

But then again, the hydraulic pump itself gets worn out, and the filter also gets dirty, causing the hitch to malfunction. The air can also get into the hydraulic system and cause malfunctions.

A faulty hydraulic cylinder can make the hitch too hard to drop or drop too slowly. The main relief valve can also be in need of adjustment, causing hitch problems.


Draining the contaminated hydraulic fluid is preferable in this situation. You must collect a small amount of transmission fluid from the reservoir and compare it to the manufacturer’s specifications.

This will help in determining whether the fluid is contaminated.

If the fluid is contaminated, replace the transmission fluid entirely. Refill it with new fluid if it isn’t up to the recommended amount.

If there are any air leaks, you need to check the pump seals, suction pipe, and fittings and patch them with putty. 

However, occasionally you can require a total replacement, depending on the leak.

Replace the pump if it breaks down rather than try to fix it. The oil filter needs to be changed as well. For the relief valve and hydraulic cylinder, replace them if there’s any tear or damage.

John Deere 4240 Transmission Problems

Problems Reasons Solutions
Hard Shifting of Gears Faulty clutch, gear shift linkage, shift forks 

Defective gear shifting mechanism 

Test & restore/ replace the faulty parts
Low Transmission Pressure Low fluid supply

Clogged filter

Defective relief valve

Refill the fluid

Clean the filter

Replace the valve

Noisy Transmission Cracked bearing

Insufficient Oil

Worn-out gears, shift forks

Change the faulty parts and refill the fluid
Transmission Oil Leakage Worn-out Gaskets & seals

Cracked transmission Housing 

Install new or repair the old components to solve Transmission Problems.

Problem 1: Hard Shifting of Gears

One of the worst transmission problems is when gears get hard to shift. Several different factors cause this issue. But to find them, you need to check all of the possible reasons behind them. 


This is mostly caused by parts being completely worn out due to long field hours. Every part of the shifting mechanism can wear out due to overuse, from a worn-out clutch to damaged shift forks.

Moreover, the shift linkage can get stuck along with the clutch. But sometimes, the shift linkage just came loose over time.


Replacing the worn-out part is the obvious solution. But let us add that doing it at home may save you a lot of money over taking it to a repair shop.

Amazon has the shift linkage for only 38 dollars. So, repairing at home may cost between $50 and $60, whereas repair shops may charge between $125 and $250.

Problem 2: Low Transmission Oil Pressure

Low transmission oil pressure indicates that there’s a low level of pressure overall. This means that when you shift gears, your transmission takes longer than usual to engage.


Low oil pressure is mostly due to insufficient oil supply. But along with insufficient oil, the oil filter might also be clogged, which hinders enough oil from passing in the first place.

Sometimes the relief valve can also be defective and cause the pressure to be low.


First, check if there’s sufficient oil in the supply compartment. If not, refill it with fresh oil. If there’s already enough oil, check the oil filter and relief valve. Test if the valve is opening and closing at the proper times.

If not, see if the issue is with the mechanism or if the valve itself is faulty. If it is worn out, replace it with a new relief valve. For a clogged oil filter, you also need to replace it.

Problem 3: Noisy Transmission 

If you hear unusual knocking sounds while shifting gears, it usually means the transmission fluid level is low. But other than low oil pressure, some parts can also be broken. Let’s check what is causing this noisy transmission.


Cracked bearings, improper gears, and damaged shift forks mostly cause this problem.

These parts get broken down over time and move around, creating noise when you crank up the engine. Surprisingly, contaminated transmission fluid and low oil levels can also contribute to this.


Faulty parts like shift forks, bearings, and improper gears should be fixed immediately after the initial inspection. If you notice that there’s insufficient oil, then refill the tank as soon as possible.

Don’t forget to check the transmission fluid compartment as well. If the fluid seems dirty, drain it and replace it with a new transmission fluid. (our pick: Ford XT-10-QLVC 5 Quart Mercon-Lv Automatic Transmission Fluid)

Problem 4: Transmission Oil leakage

Oil leaks are quite common, but the cause is not always the damaged tank or oil compartment. Here, let’s examine the probable reasons-


This is primarily due to the damaged oil compartment. This can, however, be caused by a faulty gasket or seal as well. Moreover, the transmission house cracks occasionally, making it possible for transmission oil to leak.


Replacing the seals or gaskets is the best solution for overall maintenance. For transmission housing, you need to check and see the damaged area. If it is beyond repair, replace it as soon as possible.

John Deere 4240 Steering Problems

Problems Reasons Solutions
Hard Steering Defective steering column & hydraulic steering pump 

Air in the steering system, Incorrect tire pressure  

Low oil level & Oil leakage

Worn-out hydrostatic steering unit 

Replace with new steering column & pump

Drain air and adjust the tire pressure

Fill up oil & restore oil tank

Replace hydrostatic steering unit.

Excessive Steering Wheel Play Worn-out column shaft, coupling, hydrostatic unit

Faulty tierod ends, pump failure

Check & replace the parts
The front wheel moves right or left Low tire pressure

Faulty steering linkage, or tie-rod ends, hydrostatic steering unit 

Failure of the steering cylinder 

Check and adjust the tire pressure.

Replace the faulty parts.

Problem 1: Heavy Steering

The most serious steering issue you may encounter while operating a tractor is heavy steering. Let’s take a look at what’s causing this particular problem.


In most cases, the defective steering column is to blame. But incorrect tire pressure and toe-in could also be behind this problem.

Additionally, worn-out components like a broken hydraulic steering unit or the pump can let air and oil leak. And because of this leakage, the steering oil gets used more than necessary and often runs out. 


If the steering column is defective, it’s always better to replace it than to tweak it in some places. Tire pressure can easily be adjusted along with toe-in.

For faulty or worn-out parts like the steering unit and steering pump, it is better to replace them altogether. And it will solve the air and oil leakage issues as well. 

But you can also try to drain excessive air from the steering system by opening the bleed valve.

You might also need to check the hose joints and steering pipe and tighten them accordingly. For low oil levels, simply top it off with fresh oil.

Problem 2: Excessive Steering Wheel play

Ball joints connect the steering knuckles of the tractor to its steering system. When these ball joints wear out, it usually results in excessive steering wheel play. 


A worn-out steering coupling or shaft, a faulty hydrostatic steering unit, and a faulty toe-rod end cause excessive steering wheel play. However, the failure of the steering pump is another possibility.


It is preferable to replace faulty parts rather than repair them only to have them fail again quickly. Check for wear on the steering coupling, shaft, and toe rods, and replace them as necessary.  

However, the steering pump can be repaired, though it may cost between $500 and $800. So, it is preferable to replace the motor. 

Problem 3: Front wheel Drifts Right or Left

Front-wheel wandering is one of the most frequent steering issues. Despite the fact that this issue has identified the causes behind them, one could easily ignore them


Like other steering problems; worn-out parts can also cause this drifting issue. Worn-out hydrostatic unit, steering linkage, tie-rod ends, and hub bearings can cause this uncontrollable drifting.

Along with these worn-out issues, low tire pressure and cylinder failure can cause this problem. Sometimes the front hub bearing not being properly adjusted causes this too.


Worn-out parts need to be replaced as soon as possible, but check and test the parts carefully before changing them. Sometimes the parts are simply incorrectly installed, and adjusting them properly solves the issue.

If the tire pressure seems low,  inflate them to the proper mark, but don’t go overboard with the pressure. That can cause other unwanted problems. 

Maintainance Tips John Deere 4240 Problems

To keep your tractor running for a long time, you must follow some basic maintenance guidelines. This will keep your tractor running smoothly and affordably.

However, you might need to add an extra 15-20 minutes of manual labor after fieldwork:

  • Check the engine’s air filter and oil level daily after 10 or more hours of fieldwork. Ensure that there is sufficient oil and that there has been no damage.
  • However, wait at least 15 minutes after the engine has been turned off before performing this inspection. The radiator’s water level should be topped off during daily inspections.
  • Every week, check the air pressure in your tires and drain any accumulated water in the oil filter. Ensure that the battery’s water level stays within acceptable bounds. Be sure to grease the bearings, brake control, tie rod, clutch shaft, and other moving parts to keep them in good working order.
  • Oil the starter and dynamo of the tractor once every two weeks. It’s also necessary to clean the smoke tube. Usually, carbon dirt builds up on this tube from time to time.
  • Clean the primary diesel filter every four weeks or after 250 hours of fieldwork. If there is any significant damage, replace it.
  • Make sure to change the oil in the gearbox and fill it up with clean, high-grade oil every 6 months.


That marks the end of our discussion on John Deere 4240 problems. Your tractor might occasionally experience issues with the steering or the engine.

However, with regular upkeep, your tractor should last for at least 4000 hours of fieldwork without too many problems.

Ask for help from a professional if you run into problems that seem beyond your scope of knowledge.  

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