CSF BMW F8X M3/M4/M2C Auxiliary Radiators w/ Rock Guards (Sold Individually - Fits Left and Right
Fits 2019–2021 BMW M2, 2015–2018 BMW M3 and more
All 6 applications- Authorized dealerGenuine CSF parts, sourced direct
- 30-day returnsSee the return policy
- Diesel techs on the line908-223-9744, call or text
- Secure checkout
Compared to the OEM F8X coolers, the CSF units are a significant upgrade. CSF eliminated the OE plastic mounting pod by incorporating it into the modular design that fits both sides. This design improvement increases the size of both the core and tanks. The extra space taken from the mounting pod allowed for a 7% increase in Core Size and an 10% increase in Tank Volume. With a larger 2-row 42mm core, cooling efficiency and capacity are drastically increased. The high efficiency core using CSF's Exclusive B-Tube Technology maximizes airflow and heat dissipation. 100% All-Aluminum construction ensures the best performance and durability. The mounting pins and brackets are much stronger and more durable than the OE plastic pod mounting system. In addition, the black finish provides extra protection and offers a stealthy look behind the grilles of your F8X. In addition, the CSF auxiliary radiators also feature integrated bolt on rock guards to keep the coolers safe. You've no doubt heard horror stories about OEM coolers getting punctured and spilling fluids all over the road or track. Now you can feel more confident that your cooling system is safer from road debris.
- 2026 Update: New "Track-Spec" 5mm Tall Ultra Efficient Fins with a Multi-Louvered Design for Maximum Surface Area Contact and Heat Dissipation
- High-Performance Upgrade Suitable for Professional Racing, Street Performance, or OEM Replacement
- Sold Individually - all applications require 2 auxiliary radiators
- 2-Row 42mm High-Performance Core Featuring CSF's B-Tube Technology
- Tank Volume increased by 10% and Core Size Increased by 6.4%
- True "Drop-in Fit" Requires No Modifications to Install
- 100% All-Aluminum TIG-Welded Construction
- Multi-Fit - Fits Both Left & Right Side
- OEM Style "Quick Connect" Inlet/Outlet
- Individually Leak and Pressure Tested
- Satin Black Finish for OEM+ Look
- Includes Detachable Rock Guard
- 2 Year Limited Warranty
- Brand
- CSF
- Part number
- 8258
- SKU
- CSF8258
- UPC
- 710353082584
- Category
- Radiators
- Weight
- 5.7 lb
- Shipping
- Ground, ships in 1 to 2 business days
- 2019–2021BMW M2
- 2015–2018BMW M3
- 2015–2020BMW M4
| Years | Make | Model | Submodel |
|---|---|---|---|
| 2019–2021 | BMW | M2 | Competition |
| 2020 | BMW | M2 | CS |
| 2015–2018 | BMW | M3 | Base |
| 2015–2020 | BMW | M4 | Base |
| 2019–2020 | BMW | M4 | CS |
| 2016 | BMW | M4 | GTS |
Applications are the manufacturer's published fitment for this part number.
Not sure it fits? Call 908-223-9744 or text us the year, model and engine. We confirm fitment before you order.
- Shipping
- In-stock parts ship in 1 to 2 business days. Tracking is emailed as soon as the label prints.
- Returns
- 30-day returns on unused parts in the original packaging. Return policy.
Reviews
What customers say
Verified reviews collected by Loox from real orders.
Good to know
Questions, answered straight.
If it is not here, call or text the counter. Real people, real answers.
Fitment
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Will this fit my truck?
The Fits section at the top of the page lists the manufacturer's applications for this exact part. If your year, make and model is not there, or you are not sure, text us a photo of what you are replacing with your year and engine and we will confirm it before you order.
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What if I order the wrong part?
Call or text us before it ships and we will swap it. After delivery you have 30 days to return it in new, uninstalled condition. The return policy has the restocking details.
Shipping
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When will it ship?
In-stock parts usually ship within 1 to 2 business days from warehouses across the USA. The stock line under the options tells you the status of the part you are looking at. Large items ship LTL freight and we call to schedule delivery.
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Why did I only get part of my order?
We ship from multiple warehouses, so an order with several items can arrive in more than one box. Tracking for each shipment is emailed as it goes out. Full details in the shipping policy.
Returns and warranty
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What is the return policy?
30 days from delivery, in new and uninstalled condition, with a restocking fee. Everything is spelled out in the Returns & Refund Policy.
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How do warranty claims work?
We are an authorized dealer, so the manufacturer's warranty applies to every part we sell. Call or text us with your order number and we handle the claim with the brand for you.
Paying
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Can I pay over time?
Yes. Shop Pay installments are offered at checkout on qualifying orders, and the monthly estimate shows right under the price.
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What is a core deposit?
Some remanufactured parts, like injectors and turbos, carry a refundable core deposit. It is shown on the product page when it applies and refunded when your old part comes back to us.
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Why buy here
A diesel shop that sells parts, not a website that sells boxes.
Every part on this site is one our own techs can stand behind.
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We run what we sell
A working diesel repair and fabrication shop in Nazareth, PA. These are the parts our techs install every week.
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Real techs on the phone
Call or text 908-223-9744 and you get a diesel tech, not a script.
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Authorized dealer
Genuine parts straight from the manufacturer, with the factory warranty behind them.
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Fast from stock
Most in-stock parts ship in 1 to 2 business days from warehouses across the USA.
Authorized dealer for 140+ brands
All brands- 7+ Years in business
- 6+ Shop technicians
- 30,000+ In-stock SKUs
- 25+ Trucks given away
The shop floor, Nazareth, PAFull Send Diesel, Nazareth, PA
A team of diesel people, not a call center.
Full Send Diesel is a shop full of techs, builders and parts people in Nazareth, Pennsylvania. When you call or text, you reach someone who works on these trucks and knows the parts.
Not sure what you need? Send a photo of what you are replacing with your year and engine. We will point you to the right part, confirm it is in stock, and get it moving.
Mon–Fri, 8am–4pm ET. After hours, text or email and we answer first thing in the morning.
































