
Cummins QSB 4.5L High Pressure Fuel Rail 2013-2018: OEM 3977727
CUMMINS QSB 4.5L HIGH PRESSURE FUEL RAIL 2013-2018: OEM 3977727

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured Tamerx High Pressure Fuel Rail, Tamerx part number 0 445 224 025 ( OEM Part Number 3977727 ). All parts are proudly remanufactured in the U.S.A. to the highest of OEM standards, and improvements are often applied to the original design in the remanufacturing process. This part is primarily made for a Cummins QSB 4.5L, production years 2013-2018, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
OEM NUMBERS
| Primary OEM | 3977727 |
| Additional OEM | 107785-0160, 3963815, 3977727 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490539662 |
| WEIGHT | 12.00 LBS |
SHIPPING OPTIONS
Ship Weight : 12.00 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.
Built specifically for 2013–2018 Cummins QSB 4.5L engine applications, the OEM 3977727 High Pressure Fuel Rail is designed to meet original equipment specifications for accurate fit and reliable service. This component distributes high-pressure fuel evenly to each injector within the common rail system, supporting precise fuel delivery. Manufactured with durable materials and tight tolerances, it is engineered to withstand the demanding conditions of modern diesel engines. Proper fuel rail operation is essential for maintaining consistent combustion and stable engine function. Tamerx Diesel Products LLC supplies this Cummins QSB 4.5L high pressure fuel rail as a dependable solution for maintaining efficient fuel system performance.
FITMENT CHART
| YEAR | MAKE | ENGINE(S) | ||||
|---|---|---|---|---|---|---|
| 2013 | Cummins | QSB 4.5L | ||||
| 2014 | Cummins | QSB 4.5L | ||||
| 2015 | Cummins | QSB 4.5L | ||||
| 2016 | Cummins | QSB 4.5L | ||||
| 2017 | Cummins | QSB 4.5L | ||||
| 2018 | Cummins | QSB 4.5L | ||||
PEOPLE ALSO ASKS | BLOG(S)
The Cummins QSB 4.5L High Pressure Fuel Rail OEM 3977727 is a key part of the engine’s common rail fuel system. It serves as the central distribution channel for pressurized fuel delivered by the high-pressure pump before it reaches each fuel injector.
While the fuel rail is a single assembly, it includes several core elements that allow it to function reliably within the high-pressure system:
Primary Components
- Fuel Rail Body
- The main tube or channel that holds and routes high-pressure fuel to the injectors.
- Fuel Injector Ports
- Precision machined openings where each injector mounts and seals against the rail.
- High-Pressure Inlet Port
- Connection point for pressurized fuel supplied by the high-pressure pump.
- Pressure Sensor Port
- A location for the rail pressure sensor to monitor and communicate pressure data to the engine control module.
- Mounting Points
- Bolt bosses or brackets that secure the rail to the engine assembly.
Supporting Elements
- Seals and O-Rings
- Precision seals that prevent leaks between the rail and injectors or other connections.
- Pressure Sensor (when installed)
- Detects rail pressure in real time and sends the information to the engine management system.
- Fuel Lines/Fittings
- Connections that link the rail to the high-pressure pump and return or vent circuits if applicable.
How These Parts Work Together
As high-pressure fuel enters through the inlet port, the rail body holds the fuel at a controlled pressure and delivers it to each injector through the individual ports. Seals prevent leakage at these high pressures, and the pressure sensor provides feedback to the engine control module. This enables the system to adjust pump output and ensure consistent delivery for precise fuel metering and combustion.
Together, these components allow the Cummins QSB 4.5L High Pressure Fuel Rail OEM 3977727 to support balanced fuel delivery and stable engine operation in 2013–2018 applications.
The high pressure fuel rail distributes pressurized fuel from the pump to the injectors. Because it operates under extreme pressure, even minor issues can create noticeable engine problems. Recognizing the warning signs early can help prevent further fuel system damage.
One of the most common symptoms is unstable fuel pressure.
When the rail or its related components begin to fail, you may notice:
- Hard starting or extended cranking
- Rough idle
- Engine misfires
- Sudden stalling
- Loss of acceleration
- Check engine light with fuel pressure codes
- Fluctuating rail pressure readings
In some cases, the fuel rail can develop internal cracks or external leaks. Visible fuel leakage around the rail requires immediate attention due to safety concerns.
A faulty fuel rail pressure sensor can also cause similar symptoms by sending inaccurate readings to the engine control module. This can lead to improper fuel delivery and drivability issues.
Because the high pressure fuel system works as a unit, professional diagnostics are important. A technician will test fuel pressure, inspect for leaks, and review fault codes before confirming whether the fuel rail itself is the source of the problem.
Addressing the issue promptly helps protect injectors and other critical fuel system components.
The OEM 3977727 high pressure fuel rail is the distribution manifold that supplies pressurized fuel to each injector on QSB 4.5L engines.
The 3977727 fuel rail is engineered for direct replacement on the specified QSB 4.5L applications.
Confirming OEM 3977727 ensures you select the correct rail for the specific Cummins QSB 4.5L fuel system layout.
Yes, the 3977727 fuel rail is designed to interface with the original high pressure lines and injector connections.



























































