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Volvo Mack D11, D13, MP7, MP8 Oil Separator 2014-2018: OEM 21122541

VOLVO MACK D11, D13, MP7, MP8 OIL SEPARATOR 2014-2018: OEM 21122541

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$499.95

CORE CHARGE:

$200.00
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 NUMBER 21122541
PART TYPE Oil Separator
BRAND Tamerx Diesel Products
ENGINE MAKE Volvo Mack
ENGINE TYPE D11, D13, MP7, MP8
YEAR 2014-2018
PART NUMBER 21122541
ADDITIONAL NOTES Crankcase breather

PRODUCT DESCRIPTION

This is a New, Tamerx Oil Separator, Tamerx part number 21122541 ( OEM Part Number 21122541 ).This part is primarily made for a Volvo Mack D11, D13, MP7, MP8, production years 2014-2018, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

Additional Notes: Crankcase breather

OEM NUMBERS

Primary OEM21122541
Additional OEM21122541

ADDITIONAL DETAILS

CONDITIONNew
UPC / Barcode
WEIGHT4.00 LBS

SHIPPING OPTIONS

Ship Weight : 4.00 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.


Breathe easier, drive smarter with the Volvo/Mack D11, D13, MP7, MP8 Oil Separator – OEM 21122541, perfectly crafted for 2014–2018 engines. Designed to capture crankcase oil mist with surgical precision, it keeps your intake clean, improves engine longevity, and helps reduce maintenance costs. Built to OEM standards for a seamless fit and rugged reliability, this oil separator ensures your powertrain stays efficient and trouble-free mile after mile.

FITMENT CHART

YEARMAKEENGINE(S)
2014Volvo Mack D11 D13 MP7 MP8
2015Volvo Mack D11 D13 MP7 MP8
2016Volvo Mack D11 D13 MP7 MP8
2017Volvo Mack D11 D13 MP7 MP8
2018Volvo Mack D11 D13 MP7 MP8

PEOPLE ALSO ASKS | BLOG(S)

Maintaining clean airflow within your engine isn’t just about efficiency—it’s about longevity. The Volvo Mack Oil Separator OEM 21122541, compatible with D11, D13, MP7, and MP8 engines (2014–2018), plays a crucial role in crankcase ventilation by separating oil mist from blow-by gases. Tamerx Diesel Parts delivers this vital component with OEM precision, ensuring your engine stays protected against oil contamination and harmful emissions.

  • Critical Function: Oil Mist Separation
    The oil separator intercepts oil-laden blow-by air before it re-enters the intake system, reducing the risk of oil buildup and preserving combustion efficiency.

  • Protects Your Engine Components
    By filtering out oil mist, the separator helps prevent deposit buildup, sticky valves, and fouled sensors—extending the lifespan of internal parts.

  • OEM Quality You Can Trust
    Built to OEM spec 21122541 and backed by a 1-million-mile or 1-year warranty, Tamerx ensures that this part meets the exacting standards of Volvo/Mack engines.

  • Efficient Air Flow = Cleaner Emissions
    Clean crankcase ventilation maintains proper air-to-fuel ratios, which supports smoother combustion and helps reduce environmental emissions.

  • Ease of Replacement & Core Return
    Swap in the new separator with minimal downtime. Plus, a refundable core charge (returned within 30 days) keeps costs manageable.

  • Durability for Heavy-Duty Use
    Engineered to withstand the stress of heavy workloads, the separator endures vibration and heat—making it ideal for fleet operations and long-haul runs.

For truck operators and maintenance professionals seeking durable, dependable parts, the Volvo Mack Oil Separator OEM 21122541 from Tamerx Diesel Parts offers peace of mind and efficient engine protection. Clean crankcase ventilation isn't a luxury—it’s a necessity for safeguarding performance, emissions, and long-term reliability. Trust Tamerx for parts that keep your engine running cleaner, smoother, and longer.

An oil separator is designed to remove oil from the crankcase ventilation system before it’s reintroduced into the intake. This prevents oil from contaminating the intake air and keeps the engine running cleanly. When an oil separator begins to fail, it can lead to performance problems, increased emissions, and even long-term engine damage if left unaddressed.

Common Signs of Oil Separator Failure

  • Excessive Oil Consumption
    One of the first signs of a failing oil separator is unusually high oil usage. If the separator is no longer capturing and returning oil to the crankcase, more oil may burn in the combustion chamber.

  • Blue Smoke from the Exhaust
    Oil bypassing the separator can enter the intake and get burned in the cylinders, producing bluish smoke from the exhaust—especially noticeable during acceleration or high RPMs.

  • Oil Leaks or Drips
    A malfunctioning oil separator may cause oil to back up or leak around engine seals or hoses. These leaks often appear around the valve cover or intake manifold.

  • Poor Engine Performance
    Oil contamination in the intake system can lead to carbon buildup on valves and sensors, resulting in rough idling, misfires, or reduced throttle response.

  • Check Engine Light (CEL)
    A clogged or faulty oil separator can affect the air-fuel ratio or create vacuum leaks, triggering a diagnostic trouble code and illuminating the check engine light.

  • Whistling or Hissing Noises
    A damaged diaphragm in the separator can cause abnormal noises as it fails to regulate crankcase pressure properly.

A failing oil separator can lead to increased emissions, decreased fuel efficiency, and potential damage to internal engine components if not addressed promptly. If you notice any of these symptoms—especially blue smoke or rising oil consumption—it’s wise to inspect or replace the separator. Regular maintenance and timely diagnostics will help ensure your engine remains clean and efficient.

By inspecting for oil pooling inside the housing and checking the cleanliness of the breather port area.

Perform scheduled visual inspections and clean or replace the separator when oil accumulation is noticeable.

Wipe the external surfaces with a clean rag; internal cleaning generally involves replacing rather than attempting to wash the unit.

A blockage increases crankcase pressure, which can cause oil leaks or even damage seals and gaskets.

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