BMW M4 S55 3.0L Twin-Turbo Inline-6 Engine

BMW M4 S55 Engine for Sale | Low Mileage 3.0L Twin Turbo Inline 6 | McClain Auto Part

Product Overview

If you are searching for a BMW M4 S55 engine for sale, McClain Auto Part carries genuine OEM BMW M division S55 3.0L twin turbo inline 6 engines sourced from verified low-mileage donor vehicles and inspected at our Cleveland, Ohio warehouse before anything ships. We have been supplying used performance engines to mechanics, independent BMW specialists, and enthusiasts across all 50 states since 2009. Every S55 engine we sell is compression tested on all six cylinders, rod bearing condition documented, twin turbocharger system inspected, and backed by a 6-month warranty. Buyers choose a verified OEM S55 over rebuilt alternatives because they get the complete factory M division assembly with documented mileage, known bearing condition, and direct fitment for M3, M4, and M2 Competition replacement or swap applications at a price that makes sense.

Product Highlights

Genuine OEM BMW M division S55 3.0L twin turbo inline 6 engine
Low mileage verified from donor vehicle records
Compression tested on all six cylinders, actual numbers recorded
Rod bearing condition inspected and documented on every unit
Twin turbocharger assembly inspected for shaft play and housing condition
Oil condition checked for metal contamination and bearing distress indicators
Coolant passages inspected for mixing or head gasket issues
Double VANOS units checked for condition and solenoid integrity
No audible knocking, ticking, or unusual noise confirmed before packaging
6-month warranty against internal mechanical defects
Nationwide freight shipping within 1 to 3 business days
Real inventory in our Cleveland warehouse, not a brokered listing
VIN compatibility confirmation available before ordering

The BMW S55 Engine Platform

BMW developed the S55 specifically for M division applications in the F80 M3, F82 and F83 M4, and F87 M2 Competition. It shares the basic inline 6 configuration with the N55 production engine but is a purpose-built M division unit rather than a detuned version of a standard BMW powerplant. The S55 uses a different cylinder head casting, revised aluminum block, upgraded connecting rods and crankshaft, double VANOS variable valve timing on both intake and exhaust camshafts, and a twin scroll twin turbocharger system in place of the single turbo found on the N55.

The result is 425 horsepower and 406 lb-ft of torque from 3.0 liters of displacement in factory M4 trim, with rev capability and throttle response characteristics that reflect the M division’s engineering priorities rather than the packaging and emissions compromises of the standard production lineup.

The S55 established itself as one of the most capable turbocharged inline 6 engines BMW has produced in the modern M era and remains highly sought after for both direct replacement and swap applications as F80 and F82 chassis continue to age into the performance used market.

Twin Scroll Turbocharger System

The S55 uses two small twin scroll turbochargers rather than a single larger unit. Twin scroll technology separates exhaust pulses from cylinder pairs into dedicated scroll channels within each turbine housing. This separation reduces turbocharger spool time and produces throttle response at partial load that feels significantly closer to a naturally aspirated engine than a traditional single large turbo configuration.

For replacement applications, the twin turbocharger assembly condition on the specific unit is documented before shipping. Shaft play, housing condition, and oil feed line integrity are assessed on both turbocharger units during inspection. Buyers receive the condition documentation on both turbos before the order is finalized.

S55 Versus N55: Understanding the Difference

If you are sourcing a replacement for an M3 or M4, the S55 is the correct engine. The N55 is the standard production 3.0L single turbo found in the 335i, 435i, and similar non-M applications. Both engines share a basic inline 6 architecture and 3.0L displacement, but the differences between them are extensive and consequential.

The S55 carries a different cylinder head, twin scroll twin turbos versus a single twin scroll turbo, upgraded connecting rods, a revised crankshaft, a higher-capacity oil system, and M-specific VANOS calibration. Output differs by approximately 100 horsepower at factory specification. The two engines are not interchangeable in any direction. If your M3 or M4 needs an engine, source an S55. Do not source an N55 regardless of price or availability.

Rod Bearing Consideration

The S55 rod bearing wear pattern is one of the most thoroughly documented issues in the BMW M community and deserves direct, honest discussion before any S55 purchase decision.

The factory rod bearing specification on the S55 is a known wear item under sustained high-RPM operation, track use, and oil service intervals longer than BMW’s recommended schedule. Higher mileage S55 engines that have seen track use or aggressive street driving without consistent rod bearing service are the most common failure candidates. The failure mode is a spun rod bearing leading to catastrophic internal damage, which is why the BMW M community discusses this issue as extensively as it does.

We inspect every S55 unit for rod bearing condition indicators before it ships. Oil condition is assessed for metal particulate that indicates bearing distress. Bearing clearance indicators are documented where accessible. This documentation is provided to the buyer before the order is processed so both parties understand exactly what is being sold.

Most experienced BMW M specialists recommend replacing rod bearings at the time of engine installation regardless of the replacement unit’s mileage. ACL and Mahle rod bearings in the correct S55 specification are the most widely used aftermarket choices. This procedure is straightforward on the bench before installation and eliminates the primary long-term failure risk on the S55 platform going forward. We advise on specification and procedure when you call.

Technical Specifications

Specifications vary slightly by model year and market configuration. Contact us with your VIN before ordering to confirm the correct variant for your specific vehicle.

Vehicle Compatibility

Factory Applications

BMW M3 F80 sedan, 2015 to 2018
BMW M4 F82 coupe and F83 convertible, 2015 to 2020
BMW M2 Competition F87, 2019 to 2021

M2 Compatibility Note

The standard BMW M2 used the N55 single turbo engine, not the S55. Only the M2 Competition variant from 2019 onward received the S55. Confirm your M2 build sheet or VIN before ordering to verify S55 fitment. Ordering an S55 for a standard M2 application results in an incompatible unit.

Minor Model Year Variations

The S55 went through minor updates across its production run from 2015 to 2021. Specific external component configurations, sensor locations, and ancillary mounting details can vary between early and late production units. Provide your VIN and build date when you contact us and we confirm the correct configuration match for your specific vehicle before anything ships.

Common Swap Applications

The S55 twin turbo inline 6 is an increasingly popular swap engine for BMW enthusiasts building classic and modified chassis. Common swap applications include:

E30, E36, and E46 BMW chassis high-output builds
E9x M3 builds using the S55 over the original S65 V8
Custom tube chassis and dedicated track car builds
Kit car applications requiring a compact high-output inline 6

For swap applications, confirm engine mount dimensions, oil pan clearance, cooling system routing requirements, and DME solution before ordering. The S55 fuel and ignition systems require a functioning DME solution to operate correctly.

What Is Included

Standard With Most Units

Complete S55 long block assembly including block, head, and valvetrain
Intake manifold and charge pipe connections
Direct injection fuel rails and injectors
Valve covers
Oil pan
Twin turbocharger assembly, condition documented
Double VANOS units, intake and exhaust
Oil filter housing

Available on Select Units or Upon Request

Engine wiring harness
ECU and DME
Intercooler and charge pipe system
Front accessory drive components
Coil packs and ignition components
Oil cooler assembly

Not Included Unless Specifically Confirmed

Transmission
Flywheel or flexplate
Engine mounts
Exhaust manifolds

A Note on DME and Wiring

The S55 DME is coded to the vehicle VIN. For a direct factory replacement in the original car, your existing DME is typically reused and coding is performed to match the replacement engine. For a swap application or replacement in a different chassis, DME coding and VIN matching requires planning before installation. Tell us your specific application when you call and we advise on what the DME and wiring situation requires for your build.

Inspection Process

Every BMW S55 engine that ships from our Cleveland warehouse goes through a documented hands-on inspection. The twin turbo system, rod bearing condition indicators, and direct injection fuel system on the S55 require specific inspection attention that simpler naturally aspirated engines do not.

Compression Test

We compression test every cylinder before listing any S55 engine. Actual pressure readings are recorded for all six cylinders. We do not perform a visual pass and call it tested. Any cylinder showing significant variance from the others is flagged and the unit is assessed further before a listing decision is made.

Rod Bearing Condition Assessment

Oil is drained and inspected specifically for metal particulate that indicates rod bearing distress. Fine metallic sheen is expected in used engine oil. Visible metal flakes or chunks indicate active bearing wear and disqualify a unit from our inventory. Bearing clearance indicators are documented where accessible during inspection.

Twin Turbocharger Inspection

Both turbocharger units are inspected for shaft play, housing condition, compressor wheel condition, and oil feed and return line integrity. A turbocharger with excessive shaft play indicating bearing failure is documented and disclosed. The condition of both turbos is reported separately before the order is finalized.

Oil and Coolant Inspection

Engine oil is inspected for coolant contamination and metal particulate. Coolant passages are inspected for oil contamination that indicates head gasket compromise. A milky appearance in the oil or visible oil contamination in the coolant circuit disqualifies a unit.

VANOS and Valvetrain Inspection

Double VANOS units on both intake and exhaust are checked for solenoid connector integrity and external condition. Valvetrain cover surfaces are inspected for leaks and seal condition.

Direct Injection Fuel System

Fuel rail and injector seal condition are assessed. High pressure fuel pump drive condition on the intake camshaft is noted during inspection.

Audible Assessment

No audible knocking, ticking, rod knock, or unusual engine noise is confirmed before packaging. Audible assessment results are documented before shipping.

Shipping Preparation

After passing inspection, the engine is drained of fluids, all open ports are plugged, and the assembly is mounted and secured on a certified freight pallet. The unit is wrapped and strapped before handoff to the carrier.

Installation Notes

Rod Bearing Replacement on Installation

Given the documented rod bearing wear pattern on the S55 platform, most experienced BMW M specialists recommend replacing rod bearings at the time of engine installation regardless of the replacement unit’s mileage. This procedure is performed on the bench before the engine goes into the car and eliminates the primary long-term failure risk. ACL and Mahle rod bearings in the correct S55 specification are the standard choices. We advise on rod bearing specification and sourcing when you call.

DME Coding

S55 DME coding to the replacement engine is a required step for direct factory replacement applications. Confirm your independent BMW specialist or dealer service department can perform S55 DME coding before ordering the engine. This is not an optional step and skipping it results in fault codes and reduced engine management function.

High Pressure Fuel Pump

The S55 high pressure direct injection fuel pump is driven off the intake camshaft. Pump condition on the replacement unit is noted during inspection. Given that the high pressure fuel pump is a wear item on higher mileage S55 engines, replacement at installation alongside the rod bearing service is worth planning for on any unit with significant mileage.

Charge Air Cooling System

The S55 uses a separate cooling circuit for the charge air cooling system in addition to the main engine cooling circuit. Both circuits must be properly flushed, filled with the correct coolant specification, and fully bled before startup. Air pockets in the charge air cooling circuit reduce intercooler efficiency and produce heat soak symptoms under hard driving that are easy to misdiagnose as engine issues.

Transmission

The S55 was paired with the ZF-based DCT dual clutch transmission or the 6-speed manual in factory applications. Both use a standard BMW M bellhousing pattern. Confirm your transmission and clutch configuration before ordering and confirm that DME and mechatronics coding requirements for the DCT application are addressed in your installation plan.

Cooling System Flush

Flush and refill the full cooling system including the charge air cooling circuit before initial startup on any S55 replacement. BMW HOAT coolant specification is required. Do not mix coolant types in the S55 cooling circuits.

Shipping Information

S55 engines ship nationwide from our Cleveland, Ohio warehouse via freight carrier. Every engine is mounted on a certified pallet, all ports plugged, wrapped and strapped before handoff to the carrier.

Most S55 engine orders are processed and ready for freight pickup within 1 to 3 business days of purchase confirmation and payment. You receive a tracking number as soon as the engine leaves our facility. Freight delivery to most continental US locations takes 3 to 7 business days after pickup.

Local pickup is available for buyers in the Cleveland, Ohio area by prior arrangement. Contact us before visiting to confirm the specific unit is ready and staged.

Contact us at +1(216) 230-5433 or sales@mcclainautopart.com before ordering to confirm current availability, exact mileage, rod bearing documentation, turbocharger condition, and included components on the current unit.

Warranty

Every BMW S55 engine from McClain Auto Part ships with a 6-month warranty against internal mechanical defects. Rod bearing condition indicators and turbocharger condition are documented and disclosed before the sale is processed so both parties understand exactly what is being sold.

The warranty covers internal mechanical failures resulting from defects present in the engine at the time of sale. It does not cover damage from detonation, oil starvation from installation errors, cooling system failures from improper bleeding, or damage from skipping recommended installation procedures including rod bearing replacement and DME coding.

If a covered mechanical issue arises within the warranty period, contact our team. We review the situation and work toward a fair resolution including a replacement engine, credit, or repair guidance depending on the specific circumstances. James McClain has honored warranty claims since 2009 without unnecessary complications.

Why Buy From McClain Auto Part

James McClain founded this business in Cleveland, Ohio in 2009 with one standard: sell a part you would put in your own vehicle. That standard applies to every S55 engine we list.

Every S55 in our inventory is physically in our Cleveland warehouse before it is listed. We do not broker engines from other suppliers or list inventory we have not personally inspected. When you call us about a BMW M4 S55 engine for sale you talk to someone who understands the rod bearing wear pattern specific to this platform, knows the turbocharger inspection points that matter on a twin scroll twin turbo assembly, and can give you accurate information about the exact unit in current inventory before you commit to the purchase.

We carry a 4.9 out of 5 star rating on Google from over 800 verified customer reviews. Our customers include independent BMW specialists, M division enthusiasts doing direct replacements, and custom build shops sourcing S55 engines for swap projects. The consistency of our inspection process and our warranty follow-through are the reasons they keep coming back.

Frequently Asked Questions

What Vehicles Use the BMW S55 Engine

The S55 was factory-fitted in the BMW M3 F80 from 2015 to 2018, the BMW M4 F82 coupe and F83 convertible from 2015 to 2020, and the BMW M2 Competition F87 from 2019 to 2021. The standard M2 used the N55, not the S55. Confirm your VIN before ordering.

What Is the Difference Between the S55 and N55

The S55 is the M division engine with twin scroll twin turbos, upgraded internals, double VANOS on both camshafts, and 425 horsepower. The N55 is the standard production 3.0L single turbo found in non-M applications with approximately 300 to 320 horsepower. They are not interchangeable in any direction.

Is This a Direct Replacement for My M3 or M4

Yes, for F80 M3 and F82 F83 M4 applications equipped with the S55. DME coding to the replacement engine is required. Confirm your shop can perform S55 DME coding before ordering.

What About the Rod Bearing Issue

Rod bearing condition indicators are inspected and documented on every unit before shipping. We recommend replacing rod bearings at installation regardless of mileage. We advise on ACL and Mahle specification choices and procedure when you call.

How Many Miles Are on the Engine

Mileage is verified from donor vehicle records before listing. We give you the exact mileage on the specific unit before you commit to the order. Contact us for current unit mileage.

Is the Engine Compression Tested

Yes. Every cylinder is compression tested before the unit ships. Actual pressure readings are recorded on all six cylinders and are available on request before purchase.

Does the Engine Include the Turbos

Yes. The twin turbocharger assembly is included with most units. Shaft play, housing condition, and oil feed line integrity are documented on both turbos before shipping.

Does It Include a DME and Wiring Harness

Not automatically. DME and wiring harness availability varies by unit. Tell us your specific application and we confirm what is available with the current unit in inventory.

What Does the Warranty Cover

Six months from purchase against internal mechanical defects. Rod bearing condition and turbocharger condition are disclosed and documented before the sale. Contact us if a covered issue arises within the warranty period.

Can I Use This Engine for a Swap

Yes. The S55 is used in E30, E36, E46, and E9x BMW chassis swap builds as well as custom tube chassis and track car projects. For swap applications confirm engine mount dimensions, oil pan clearance, cooling system routing, and DME solution before ordering.

How Is the Engine Shipped

Every S55 ships on a secured freight pallet from our Cleveland warehouse with all ports plugged and the assembly fully protected for transit. Most orders are processed within 1 to 3 business days. You receive a tracking number when the engine ships.

Do You Ship Nationwide

Yes. We ship S55 engines to all 50 states via freight carrier from Cleveland, Ohio.

Can I Pick Up the Engine Locally

Yes. Local pickup is available for buyers in the Cleveland, Ohio area by prior arrangement. Contact us before visiting to confirm the unit is ready.

How Do I Place an Order

Call us at +1(216) 230-5433 or email sales@mcclainautopart.com. Provide your VIN and application before ordering. We confirm availability, exact mileage, rod bearing documentation, turbocharger condition, DME availability, and fitment before processing your order.

Conclusion

A genuine OEM BMW M4 S55 engine for sale from McClain Auto Part means a compression-tested, rod bearing-documented, twin turbo-inspected M division inline 6 from a verified low-mileage donor vehicle shipped directly from our Cleveland warehouse. The most important steps before ordering are VIN confirmation for your specific M chassis variant and confirming your shop can perform S55 DME coding before installation. Call us at +1(216) 230-5433 or email sales@mcclainautopart.com with your VIN and application details. We confirm the correct variant, review current unit documentation including rod bearing and turbocharger condition, and answer every question before you commit to the purchase.

Clean S55 inventory is limited by the production volume of the M3 and M4 platforms. If you have questions before ordering, ask them now.