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BMW S65B40 Engine - Replacement Cost, Problems & CompatibilityProblems & Compatibility
The BMW S65B40 is a 4.0-litre naturally aspirated V8, fitted exclusively to the E90/E92/E93 M3 from 2007 to 2013. Reconditioned S65B40 units are available from around £6,500 ; the engine generated approximately 410 UK replacement requests in 2025 [EM-VERIFIED].
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Key Specs
BMW S65B40 - Specifications at a Glance
Engine Code
S65B40
Fuel
Petrol
Configuration
4.0L V8, naturally aspirated, DOHC, 32-valve
Power Output(s)
414 hp (309 kW) @ 8,300 rpm; 295 lb-ft (400 Nm) @ 3,900 rpm
Years Produced
2007-2013
UK Models Fitted
3 models - full list in Compatibility below
2025 UK Replacement Requests
410 [EM-VERIFIED]
Replaced
S54B32 - BMW S54 Engine
Replaced By
S55B30 - BMW S55B30 Engine
Most Common Failure
Rod bearing wear (tight factory clearances)
Reconditioned Price Range
£6,500-£9,500 supply-only
Vetted UK specialists for S65B40 replacements
Minimum 12-month warranty on reconditioned and rebuilt options
Fitted To
Which BMW Models Use the S65B40-
The S65B40 was the first and only V8 engine fitted to the BMW M3, powering the E90 (saloon), E92 (coupé) and E93 (convertible) generations from 2007 through to 2013. It remains one of the most celebrated naturally aspirated M engines ever produced.
| Model | Generation/Chassis | Badge(s) | Years | Link |
|---|---|---|---|---|
 BMW M3 Saloon | E90 | M3 | 2007-2011 | |
 BMW M3 Coupé | E92 | M3 | 2007-2013 | |
| BMW M3 Convertible | E93 | M3 | 2008-2013 |
02
BMW M3 Coupé
03
BMW M3 Convertible
CROSS-BRAND
S65B40 is documented across 3 BMW applications spanning BMW M3 Saloon, BMW M3 Coupé, BMW M3 Convertible. Registration lookup confirms the exact suffix before quotes are sent.
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Not sure which engine your car has- Enter your registration above - we'll confirm your exact S65B40 fitment before any quotes are sent.
Prices
BMW S65B40 Engine Replacement Cost (UK)
Condition | Supply Only | Fitted (Independent Specialist) | Typical Warranty |
|---|
All pricing guidance shown here is indicative.
Labour Guide
Fitting an S65B40 typically takes 12-16 hours at £75-£95/hr (independent BMW M specialist) - confirm exact labour when comparing quotes.
Price Factors
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Common Problems
BMW S65B40 Engine Problems - What Actually Fails
Every engine has its weak points. Here are the known issues with the S65B40, based on real-world data and verified failure patterns.
Verified issue focus: Rod bearing wear (tight factory clearances).
1. Rod bearing wear - the S65's biggest weakness
1. Rod bearing wear - the S65's biggest weakness
Typical onset:
60,000-80,000 miles
What happens:
The factory rod bearings have excessively tight clearances, leading to premature wear and, in severe cases, catastrophic engine failure. The original tin-aluminium bearings are prone to starving of oil at high RPM, particularly when the engine is cold or during sustained high-G cornering. Symptoms include metallic shavings in the oil, a knocking sound from the bottom end, and eventual bearing spin - which typically writes off the crankshaft and often the entire engine.
Repair vs replace:
Preventative rod bearing replacement (around £1,500-£2,500 at an M specialist) is strongly recommended at 60,000 miles and is far cheaper than a full engine replacement. If the bearings have already failed and damaged the crank, a full rebuild or replacement is almost always required. Read our full rod bearing failure guide
Read more about this issue
2. Throttle actuator failure
2. Throttle actuator failure
Typical onset:
60,000-100,000 miles
What happens:
The S65 uses individual throttle bodies actuated by electric motors. The internal gears in the throttle actuators wear over time, causing drivetrain malfunctions, reduced power and, in some cases, complete throttle failure. This is a well-documented issue across the S65 platform.
Repair vs replace:
The actuators can be rebuilt (gear replacement) or replaced entirely. Repair is significantly cheaper than replacement and is a viable option.
Read more about this issue
3. Oil consumption
3. Oil consumption
Typical onset:
80,000+ miles
What happens:
Like many high-revving performance engines, the S65 can develop increased oil consumption as it ages. Consumption of up to 1 litre per 1,000 km is not uncommon on higher-mileage units.
Repair vs replace:
Regular oil level monitoring and top-ups are the standard approach. If consumption becomes excessive, valve stem seals or piston rings may need attention - this typically requires a rebuild.
Read more about this issue
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Engine Variants
How to Confirm You Have the S65B40
The S65B40 is a specific engine code within the S65 family, not a code that fragments into multiple UK-market sub-codes. The S65 family includes: - S65B40 - 4.0L, 414 hp, fitted to standard E90/E92/E93 M3 (UK market) - S65B44 - 4.4L, 444 hp, fitted to limited-production M3 GTS and M3 CRT (not UK-market regular production) The S65B40 is sometimes referred to as S65B40A in BMW parts systems. How to confirm your code: 1. On the engine - the S65B40 code is stamped on the engine block. Look for "S65B40A" on the identification plate on the left-hand side of the engine. 2. On the V5C logbook - the engine number is listed; cross-reference with BMW parts systems. 3. VIN decode - use a BMW VIN decoder; E9X M3 vehicles will show engine type "S65B40A". 4. Registration lookup - enter your reg above and we'll confirm the exact fitment. Similar-looking codes it is commonly confused with: - BMW S55B30 - the turbocharged straight-six successor in the F80 M3; not related and not a swap - BMW S54B32 - the straight-six predecessor in the E46 M3
Why fitting the wrong revision matters: The S65B40 is unique to the E9X M3. The S65B44 (4.4L) from the GTS is not a direct fit for standard M3s without significant modification, and the S55 is a completely different engine family (turbo straight-six) requiring full drivetrain and electrical changes.
Easily Confused
BMW S54B32
- the legendary straight-six from the E46 M3, producing 338 hp from 3.2 litres. The S65B40 replaced it with a V8 configuration, adding 76 hp and a higher 8,300 rpm redline, but also introduced the rod-bearing issues that the S54 largely avoided.
Alternative / Next-Gen Code
BMW S55B30
- the twin-turbo straight-six that replaced the S65 in the F80 M3 and F82 M4. It produces 425-450 hp with significantly more torque than the S65, but purists regard the naturally aspirated S65 as the last great high-revving M engine.
Confirm the exact S65B40 fitment
Why fitting the wrong revision matters: The S65B40 is unique to the E9X M3. The S65B44 (4.4L) from the GTS is not a direct fit for standard M3s without significant modification, and the S55 is a completely different engine family (turbo straight-six) requiring full drivetrain and electrical changes.
Buying Guide
Buying a Replacement S65B40 - What to Choose
Choosing the right replacement route depends on your budget, risk tolerance, and ownership goals. Here's a breakdown of your options.
Used:
A used S65B40 makes sense only if the donor engine has documented proof of recent rod bearing replacement (within the last 20,000 miles) and full service history with 10W-60 oil. The primary risk with used units is undisclosed bearing wear - insist on an oil analysis and bore scope before purchase. For lower-value E9X M3 examples, a used unit with proven bearings can be a cost-effective option. View used engines
Reconditioned:
A proper S65B40 recon includes new rod bearings (upgraded clearance bearings from ACL or BE Bearings), new throttle actuators, new VANOS components, fresh gaskets and seals, and a full machining check of the crankshaft and block. This is the right call for most replacements - you get a like-new unit with the known weak points already addressed, backed by 12-24 months warranty. View reconditioned engines
Rebuilt:
A full rebuild is justified for high-value, low-mileage or collectable E9X M3s where originality matters. An upgraded rebuild should include BE or ACL rod bearings with increased clearance, ARP main studs, and a full crankshaft polish or replacement if scored. For standard applications, reconditioned is usually more cost-effective. View rebuilt engines
Supply & Fit Line:
All engines can be supplied and fitted through our network of vetted UK BMW M specialists - nationwide coverage with 12-month warranty on labour and parts. View supply & fit
Vehicle Value Note:
The S65B40 sits exclusively in E9X M3s, which currently range from £10,000-£35,000 depending on condition, mileage and specification (saloon, coupé, convertible). A £6,500-£9,500 reconditioned engine plus £1,000-£1,500 fitting is a significant investment - typically 30-60% of the vehicle's value. For lower-value examples (sub-£12,000), carefully evaluate the car's overall condition, bodywork and interior before committing to a replacement. For collectable low-mileage or special-edition cars, the investment is usually justified.
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Related Engines
Engines Related to the BMW S65B40
Explore engines that are closely related to the BMW S65B40, including its predecessor, successor, and key family variants.
Predecessor
BMW S54B32
- the legendary straight-six from the E46 M3, producing 338 hp from 3.2 litres. The S65B40 replaced it with a V8 configuration, adding 76 hp and a higher 8,300 rpm redline, but also introduced the rod-bearing issues that the S54 largely avoided.
Successor
BMW S55B30
- the twin-turbo straight-six that replaced the S65 in the F80 M3 and F82 M4. It produces 425-450 hp with significantly more torque than the S65, but purists regard the naturally aspirated S65 as the last great high-revving M engine.
FAQ
BMW S65B40Frequently Asked Questions
Question 1How much does a BMW S65B40 engine replacement cost in the UK-
A reconditioned S65B40 supply-only costs around £6,500-£9,500, with fitted prices at £7,500-£11,000 including 12-16 hours of labour at BMW M specialist rates (£75-£95/hr). Used units start at £4,500 supply-only. Reconditioned units include new rod bearings, throttle actuators and gaskets. Prices estimated based on specialist-market consensus. Fitted prices include 12-month warranty on parts and labour.
- Reconditioned units include new rod bearings, throttle actuators and gaskets
- Prices estimated based on specialist-market consensus
- Fitted prices include 12-month warranty on parts and labour
Question 2What are the common problems with the BMW S65B40 engine-
The S65B40's most critical weakness is rod bearing wear due to tight factory clearances, typically appearing at 60,000-80,000 miles. Other issues include throttle actuator failure (gears wear out) and increased oil consumption at higher mileage. Rod bearing failure can write off the entire engine. Preventative bearing replacement costs £1,500-£2,500. Throttle actuator rebuild is cheaper than replacement.
- Rod bearing failure can write off the entire engine
- Preventative bearing replacement costs £1,500-£2,500
- Throttle actuator rebuild is cheaper than replacement
Question 3Which BMW models use the S65B40 engine-
The S65B40 powered the E90 (saloon), E92 (coupé) and E93 (convertible) M3 from 2007 to 2013. All UK-market examples are 4.0-litre 414 hp versions; the 4.4-litre GTS variant is extremely rare and not UK-market regular production. 2007-2011 for saloon; 2007-2013 for coupé/convertible. Enter your registration to confirm exact fitment.
- All E9X M3s except GTS/CRT use the S65B40
- 2007-2011 for saloon; 2007-2013 for coupé/convertible
- Enter your registration to confirm exact fitment
Question 4Should I buy a used or reconditioned S65B40 engine-
A used S65B40 is only worth considering if it has documented proof of recent rod bearing replacement (within 20,000 miles) and full service history with 10W-60 oil. A reconditioned unit is safer, as it includes new bearings, actuators and seals with 12-24 months warranty, typically costing £6,500-£9,500 supply-only. Used engines risk undisclosed bearing wear. Reconditioned units address known failure points. For collectable examples, reconditioned is strongly recommended.
- Used engines risk undisclosed bearing wear
- Reconditioned units address known failure points
- For collectable examples, reconditioned is strongly recommended
Question 5How do I know if my BMW has the S65B40 engine-
The S65B40 is stamped on the engine block (left-hand side) with "S65B40A" on the identification plate. You can also decode your VIN - E9X M3s show engine type "S65B40A". Enter your registration above for confirmation. The V5C logbook lists the engine number. BMW VIN decoders distinguish S65B40 from S65B44 (GTS). All standard UK-market E9X M3s are S65B40.
- The V5C logbook lists the engine number
- BMW VIN decoders distinguish S65B40 from S65B44 (GTS)
- All standard UK-market E9X M3s are S65B40
Question 6Is the S65B40 reliable if I replace the rod bearings-
Yes - with the rod bearings addressed preventatively, the S65B40 is a robust and durable engine. Many owners report 100,000+ miles without major issues beyond routine maintenance. The throttle actuators are also fixable, and oil consumption is manageable with regular top-ups. Preventative bearings are the single most important upgrade. Use BE or ACL bearings with increased clearance. Regular oil changes with 10W-60 are essential.
- Preventative bearings are the single most important upgrade
- Use BE or ACL bearings with increased clearance
- Regular oil changes with 10W-60 are essential
Compare BMW S65B40 Engine Prices Today
Comparing S65B40 engine prices on EnginesMarket is free, fast and carries no obligation. Enter your registration once and receive quotes specific to your E9X M3's exact engine code and specification. Our vetted UK suppliers understand the S65's rod-bearing and throttle-actuator challenges - no guesswork, no generic quotes. With reconditioned S65B40 units from around £6,500 and used units from £4,500, comparing takes two minutes and could save you thousands on a high-quality replacement.
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Minimum 12-Month Warranty
Minimum 12-month warranty on reconditioned and rebuilt options
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