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John Deere 3TNV86 High Pressure Fuel Rail 2014-2021: OEM MIA882839

JOHN DEERE 3TNV86 HIGH PRESSURE FUEL RAIL 2014-2021: OEM MIA882839

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$1,195.00

CORE CHARGE:

$150.00
iCORE DISCLAIMER: The CORE charge is a 30 day hold and will not be processed as long as the CORE is returned within 30 days. If you do not have a CORE or fail to return the CORE within 30 days, the CORE charge hold amount will be processed at that time.

AVAILABILITY IN STOCK
OEM NUMBERMIA882839
PART TYPEHigh Pressure Fuel Rail
BRANDBosch
ENGINE MAKEJohn Deere
ENGINE TYPE3TNV86
YEAR2014-2021
PART NUMBER129A00-57000
APPLICATION NOTESTier 4 Final

PRODUCT DESCRIPTION

This is a New, Bosch High Pressure Fuel Rail, Bosch part number 129A00-57000 ( OEM Part Number MIA882839 ).This part is primarily made for a John Deere 3TNV86, production years 2014-2021, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

OEM NUMBERS

Primary OEMMIA882839
Additional OEM129A-57000, MIA882839

ADDITIONAL DETAILS

CONDITIONNew
UPC / Barcode00840490542389
WEIGHT5.00 LBS

SHIPPING OPTIONS

Ship Weight : 5.00 LBS
UPS Ground, 2nd Day Air, Next Day Air

SHIPPING POLICY

Tamerx Diesel Products ships via UPS Ground. Next day air shipping can be arranged for a reasonable price of anywhere from $50.00 - $100.00 depending on the weight of the product and your location. We will do everything we can to make sure that you get the service you need. We understand how important it is to receive your order as quickly as possible.
In most cases Tamerx Diesel Products only needs one address, as long as your product is shipping to the same location as your billing information. In order to eliminate credit card fraud, your billing information must match the credit card you provide.

The terms, conditions, and details of our warranty vary from product to product. Specific warranty details can be found below.

Tamerx Diesel Products provides a replacement warranty on all of our parts. The duration and mileage limitations of the warranty vary by product and are specified on the product's detail page/item listing.

Please note that the warranty covers replacement of the part and the cost of shipping the replacement part to you only. It does not cover any shop, labor, towing, or any similar or related costs. This is not a "money back guarantee".

If you experience a problem with your part or it is not functioning properly, the correct warranty procedure is to call us at (510) 257-1777 (8:00 AM - 5:00 PM ET Monday through Friday). Be sure to have your order number and/or other relevant order information ready so we can easily locate your order and resolve your issue as quickly as possible. From that point, we will review with you any troubleshooting steps that may need to be taken and other areas or systems that can be checked to rule out external problems contributing to your part's issue. If a replacement is determined to be necessary, we will then arrange for your replacement part to ship out ASAP and issue any necessary return shipping labels and/or documents.

As is the case for the majority of the diesel products sold on Tamerx Diesel Products, your part's warranty is active as soon as you install it. In some other cases, warranty activation is contingent upon you sending us your core (i.e., your old part). Tamerx Diesel Products will provide you a return shipping label for parts that have a warranty with a core return condition. When we have received your core return, the part's warranty coverage begins. We reserve the right to void the product warranty if your core is not received within the allotted time, or if it isn't received at all. If the warranty for the diesel part you are purchasing has a core return requirement, it will be clearly noted on the product detail page/item listing.

What is a Core Charge?

A core charge (also called "core deposit") is similar to the deposit you might pay for a can or bottle of soda and is a standard requirement in the auto parts industry. For example, in many states, to promote recycling, you pay a deposit when you purchase a can of soda and receive your deposit back when you return the empty can. Many automotive parts have a core charge, or core price, that works in essentially the same way as a soda can deposit.

30 Day Core Charge Hold

You authorize Tamerx Diesel Products, to hold your credit card for the specified core charge amount and that you agree to return your core with 30 days of receiving the purchased part. When we have received your core return, the hold is released and the core charge payment is canceled.

The customer, or parts buyer, is responsible for any shipping costs associated with core returns unless otherwise specified in the product listing/detail page. Tamerx Diesel Products offers prepaid UPS shipping labels (SKU numbers UPS-CR1 and UPS-CR2) for use in returning your core that are available for purchase on our website during your shopping/order process.

The shipping label you will need to use for the core return is dependent upon what part you are purchasing. UPS-CR1 is good for cores weighing up to 20 pounds. UPS-CR2 is appropriate for shipping cores weighing 21 pounds or more. You must include enough information with the core return that clearly identifies it as a.) a Core Return, and b.) contains enough information we can use to clearly associate the core return with your order. Including a copy of the invoice or packing slip that came with the original shipment, clearly marked "Core Return", is ideal. Alternately, you can include a note marked as "Core Return" that includes your order number, full name and address, and phone number or other contact information. Failure to include this information with your returned core will most likely delay any due core credit being issued and/or delay any applicable warranty activation. Core returns need to be for the exact part purchased and cannot be damaged. Substituting another part in place of the part you have purchased is not acceptable.

All fluids must be drained.

If you have purchased a set or a parts package, you will need to return cores for all components of the set. For example, if you have purchaed a high pressure oil pump with an IPR valve, you will need to return both HPOP and IPR valve cores to receive proper credit. If you have purchased an EGR cooler/EGR valve package, your core return must consist of an EGR cooler core and an EGR valve core, or core credit will not be given.

Core Charges are often mandated by state legislature, and, as such, the actual core charge and taxes on the charge may vary depending on the state in which you buy your part. The Tamerx Diesel Products core charge presented to you online today with your item is representative of the most common core charge.


Engineered for precision fuel delivery, the John Deere 3TNV86 High Pressure Fuel Rail OEM MIA882839 is designed for engines produced between 2014 and 2021. This genuine OEM component ensures consistent fuel pressure and distribution to the injectors, supporting efficient combustion and reliable engine performance. Manufactured to John Deere’s exact specifications, it provides accurate fitment, dependable operation, and seamless compatibility with the fuel system. Its durable construction is built to withstand high-pressure conditions and the demands of agricultural and industrial environments. For operators and technicians, this fuel rail offers OEM-certified quality, long-lasting reliability, and the assurance of optimal engine performance.

FITMENT CHART

YEARMAKEENGINE(S)
2014John Deere 3TNV86
2015John Deere 3TNV86
2016John Deere 3TNV86
2017John Deere 3TNV86
2018John Deere 3TNV86
2019John Deere 3TNV86
2020John Deere 3TNV86
2021John Deere 3TNV86

PEOPLE ALSO ASKS | BLOG(S)

The fuel rail in a modern common-rail diesel engine is more than just a pipe—it’s a precision pressure reservoir that ensures fuel is available at the exact pressure the injectors need. In the John Deere 3TNV86 / 4TNV86 engines, the OEM MIA882839 high pressure fuel rail performs several critical roles:

Key Functions

  • Maintain High Fuel Pressure
    • The rail holds fuel at the required high pressure so that each injector can draw it instantly when triggered. This consistent pressure is crucial for accurate injection and smooth engine response.
  • Distribute Fuel Equally to Injectors
    • It acts as a manifold, delivering pressurized fuel to each cylinder’s injector through equal paths. Equal pressure helps ensure uniform fuel delivery across cylinders, improving balance and reducing knock or misfires.
  • Dampen Pressure Fluctuations
    • Thanks to its internal volume and design, the rail helps smooth out pressure spikes and drops during injection events, reducing pulsation that could affect spray quality.
  • Support Sensor Integration
    • Many fuel rails also include or interface with pressure sensors or transducers. These sensors provide feedback to the engine control module (ECM) about the rail pressure, allowing the ECM to adjust the pump or injection timing as needed.
  • Enable Rapid Injector Response
    • Because the fuel is already at high pressure and nearby, injectors can open and close very quickly, allowing precise control over injection timing, duration, and multiple injection events per cycle.

The MIA882839 high pressure fuel rail in the John Deere 3TNV86 / 4TNV86 is a central component that ensures injectors receive stable, equal, and high pressure fuel at all times. It supports precise fuel delivery, smooth engine performance, and the engine’s ability to meet emissions and efficiency targets.

The high-pressure fuel rail is a critical part of a modern diesel or gasoline direct injection system. It distributes fuel from the high-pressure pump to the injectors at precisely regulated pressures. Because it operates under extreme stress and pressure, many drivers wonder whether it can be serviced or repaired when it starts to fail.

Can a High-Pressure Fuel Rail Be Repaired?

In most cases, no — a high-pressure fuel rail is not designed to be repaired or serviced. These components are precision-engineered and safety-critical. Once they become damaged or contaminated, the structural integrity and pressure control are compromised. Attempting to repair a fuel rail can lead to leaks, erratic pressure, or even catastrophic failure.

Common Causes of Fuel Rail Failure:

  • Fuel contamination
    • (dirt, rust, or water in the system)
  • Internal corrosion
    • caused by poor-quality fuel or moisture
  • Excessive pressure
    • from a failing fuel pump or regulator
  • Cracked or damaged fittings
    • due to vibration or over-tightening

Why Replacement Is the Only Safe Option

High-pressure fuel systems operate at tens of thousands of PSI. Even a minor flaw in the rail can cause leaks or bursts that pose serious safety risks. For that reason, manufacturers do not recommend repairs or modifications — full replacement is the only reliable solution.

How to Prevent Fuel Rail Damage

  • Always use clean, high-quality fuel.
  • Replace fuel filters at recommended intervals.
  • Keep the fuel system sealed to prevent moisture intrusion.
  • Inspect fittings and lines during routine maintenance.

A high-pressure fuel rail is not repairable or serviceable due to the precision and pressure levels involved. If it fails or becomes contaminated, replacement is the safest and most effective solution to restore proper fuel delivery and prevent engine damage.

It delivers pressurized fuel to the injectors in John Deere 3TNV86 diesel engines for precise combustion control.

Yes, a damaged or leaking fuel rail can reduce fuel pressure and lead to hard starting or stalling.

Fuel leaks, uneven idling, or pressure loss codes are common indicators of a failing fuel rail.

No calibration is needed, but verifying pressure readings after installation is recommended.

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