BMW S85 Engine Guide

The S85 is BMW's 5.0 liter V10, and BMW's service documentation describes it as BMW's first ten-cylinder petrol engine in a production car. BMW traces the design of the engine and its electronics back to Formula 1.

The V8 S65 of the E9x M3 came after it and is derived from it. In the US the S85 went into the E60 M5 sedan and the E63 M6 coupe and E64 M6 convertible. This guide only states what BMW documents support. Rod bearings are the topic most people search on this engine, so that part of the page spells out exactly what BMW has and has not documented.

S85 · 4,999 cc · 90-degree V10 · US-market M5 (E60 sedan built 09/2005-12/2009) and M6 (E63 coupe built 03/2006-07/2010, E64 convertible built 09/2006-07/2010)

Quick read

• Ownership position: IAIK, from our own shop: a good buy for an owner who keeps up the maintenance and budgets for upkeep.
• Reliability: No engine recall turned up in the NHTSA records we searched. IAIK has not seen an S85 come into our shop with an engine failure.
• Cost to own: Not established yet. We are still researching this engine.
• Power potential: Not established yet. We are still researching this engine. Factory output is in Technical Specifications.
• Main watch item: IAIK, from our own shop: the SMG transmission, and rod bearings done early as preventive work. Rod bearings are covered in their own section below.

S85 At a Glance

Question	Practical answer
Where you find it (US market)	E60 M5 sedan built 09/2005-12/2009, E63 M6 coupe built 03/2006-07/2010 and E64 M6 convertible built 09/2006-07/2010, as build months in BMW's US parts catalog.
Sold in the US?	Yes. BMW's US parts catalog lists US-market types for the E60 M5, E63 M6 and E64 M6.
Not US-market	E61 M5 Touring: not sold in US-market BMWs, per BMW's own vehicle lists (data to December 2019).
Factory output	BMW's service documentation gives 507 hp (373 kW) and about 520 Nm. BMW's US training gives 373 kW (500 bhp) at 7,750 rpm and 520 Nm at 6,100 rpm.
Power modes	BMW's service information says the engine starts in a 400 hp mode and the POWER button selects the full 500 hp mode.
Maximum engine speed	8,250 rpm
Engine oil	BMW's February 2017 oil bulletin lists BMW M 10W-60 for S54, S65 and S85 engines in all model years.
Engine oil fill	BMW's parts catalog lists an oil fill of 9.3 liters.
Reliability profile	Not established yet. We are still researching this engine.
Typical annual planning budget	Not established yet. We are still researching this engine.
Possible first-year catch-up	Not established yet. We are still researching this engine.
Largest documented exposure	BMW documents name no engine-specific failure for the S85. Rod bearings are covered in Known Failure Points and Service Items.
Before buying or modifying	Not established beyond the items listed in Known Failure Points.

Technical Specifications

Specification	Detail
Configuration	90-degree V10 with four valves per cylinder, naturally aspirated
Displacement	4,999 cc in BMW's training, 4,998 cc in BMW's service data · 92 mm bore x 75.2 mm stroke
Compression ratio	12:1
Power	373 kW (500 bhp) at 7,750 rpm in BMW's training · 507 hp (373 kW) in BMW's service documentation. Both documents give 373 kW.
Torque	520 Nm at 6,100 rpm
Maximum engine speed	8,250 rpm
Compression pressure	6.5 to 10 bar, about equal on all cylinders, as BMW lists it
Block	Alusil aluminum-silicon crankcase split at the crankshaft centerline, with a bedplate that carries cast iron bearing bridges
Cylinder spacing	98 mm
Crankshaft	Forged steel with five crankpins offset 72 degrees apart, nitro-carburized for surface hardness
Connecting rods and pistons	Forged steel cracked-cap connecting rods of 582 grams, plus or minus 2 grams, that can only be fitted one way · pistons of about 480 grams including pin and rings
Cylinder head	One-piece aluminum head with four valves per cylinder; the valve guides are not replaceable and the head cannot be machined
Valvetrain	Solid valves with 5 mm stems and box-type hydraulic tappets that do not rotate · two timing chains drive the intake camshafts and a gear drive turns the exhaust camshafts
VANOS	High-pressure Double VANOS. BMW's training gives the intake adjustment as 60 degrees of crankshaft angle in its text and 66 degrees in its comparison table, and the exhaust adjustment as 37 degrees. BMW's own documents give different VANOS oil pressures (about 70 bar, 90 bar and 115 bar), so none is stated here.
Induction	Ten individual throttle assemblies actuated by two throttle motors, one per bank
Fuel and ignition	Variable fuel pressure and ionic current measurement for knock control and misfire detection
Engine management	MSS65
Lubrication	Quasi-dry sump · four oil pumps
Engine oil	BMW M 10W-60. The source is the February 2017 oil bulletin named in At a Glance.
Oil fill and oil pan	9.3 liters fill per BMW's parts catalog. BMW's training gives the S85 oil pan capacity as 9.3 liters.
Cooling	Cross-flow cooling with a split radiator and a thermostat in the return line that opens at 79 degrees C
Coolant capacity	Not established yet.
Firing order	Not established yet.

The Insider Read

IAIK means IA-insiders knowledge. Our collected BMW technical and ownership notes.

IAIK has not seen an S85 come into our shop with an engine failure; the cars we see come in for maintenance.

In IAIK's view the S85 is very solid as long as the maintenance is kept up, and it is a good buy for an owner who wants the car for what it is and has budgeted for its upkeep after the purchase, not only for the car itself.

The weak point IAIK names on these cars is the SMG transmission, not the engine, which IAIK expects to give trouble regardless of care; in IAIK's view a manual car is more reliable.

On a lower-mileage car, around 50,000 miles, IAIK recommends replacing the rod bearings right away as preventive work; done that way, IAIK considers the car set.

IAIK has seen S85 cars at around 140,000 miles come in still running, with no engine or rod bearing estimate needed, which IAIK puts down to how those owners kept them.

Factory Deep Dive

Block and bedplate

BMW's training says the bedplate is bolted to the upper crankcase with the main bearing bolts, and that the bolt tightening procedure must be followed strictly to prevent engine failure. BMW's torque tables list new main bearing bolts for both the S85 and the S65.

Crankshaft and rods

The main bearing classification color codes are stamped onto the crankshaft. The connecting rods are asymmetrical, which allows a narrower rod and a shorter engine.

Valvetrain and VANOS

The valve keepers are a single-row clamping design that BMW says prevents the valve from turning. A gear drive links the intake and exhaust camshafts, so they always turn in opposite directions.

Oil supply

A suction pump moves oil to the rear sump, a controllable slide-valve pump feeds the filter at up to 5 bar, and two electric pumps return oil from the cylinder heads when lateral acceleration reaches 0.8 g. The oil filter housing sits behind the front bumper on the right side, and the underbody panels come off for an oil service.

Cooling and exhaust

The split radiator has an upper tank for bank 2 (cylinders 6-10) and a lower tank for bank 1 (cylinders 1-5). The water pump is belt-driven and sits directly below the thermostat housing.

Variants and market notes

BMW's parts catalog lists the S85 in the E60 M5 sedan, E61 M5 Touring, E63 M6 coupe and E64 M6 convertible, with US-market types for all but the Touring. The documents we read describe one S85, with no separate variant names.

Service Parts at a Glance

Part	BMW part number	Note
Oil filter element set	11 42 7 840 594	Current. Replaced 11 42 7 834 734. Listed for all three US models.
Oil filter cover	11 42 7 834 730	Current.
Spark plug	12 12 0 032 273	Current. Ten per car.
Ignition coil	12 13 7 841 556	Current. Ten per car. The catalog also lists 12 13 7 835 108 as current and superseded into this number.
Air filter element, left	13 72 7 834 715	Current.
Air filter element, right	13 72 7 834 714	Current.
Coolant pump, mechanical	11 51 7 838 201	Current. Replaced 11 51 7 839 062.
Thermostat	11 53 7 836 155	Current.
Hot-film air mass meter	13 62 7 839 014	Current. Two per car. Replaced 13 62 7 830 359.
Connecting rod bearing shell, red	11 24 7 841 702	Current. Ten per car. Same number the catalog lists for the S65.
Connecting rod bearing shell, blue	11 24 7 841 703	Current. Ten per car. Same number the catalog lists for the S65.

Treat a matching number as a way to find a part, not as proof of fit for your VIN. Bearing shells are fitted by size class, so confirm the class marks on your own engine.

Known Failure Points and Service Items

Rod bearings: what BMW documents do and do not say

We did not find a BMW recall, an NHTSA recall or a BMW service bulletin that names connecting rod bearing wear or failure on the S85. That is a statement about the documents we could search, not a claim that the bearings never wear.

What BMW documents do show:

• BMW's February 2017 oil bulletin calls for BMW M 10W-60 in the S85 for all model years.
• BMW's parts catalog lists red and blue connecting rod bearing shells, ten of each per car.
• BMW publishes a repair instruction for replacing all connecting rod bearings on the S85. It calls for one blue and one red shell in each connecting rod and a bearing clearance check.
• BMW's training says the main bearing classification color codes are stamped onto the crankshaft.

Not established: how often S85 rod bearings wear, at what mileage, and whether BMW sets a replacement interval. Those questions are on our research list.

IAIK, from our own shop: on a lower-mileage S85, around 50,000 miles, IAIK recommends replacing the rod bearings right away as preventive work. IAIK has also seen cars around 140,000 miles still running with no rod bearing or engine estimate needed. IAIK gives no rate or mileage for bearing wear.

01 Recall 12V-126: positive battery cable bulkhead connector

NHTSA recall 12V-126 covers certain model year 2006-2010 M5 and 2007-2010 M6 cars, along with 2004-2010 5 Series and 6 Series. BMW says the bulkhead connector for the positive battery cable may have been attached incorrectly to the trunk floor panel, the bolt can loosen and the connection can overheat and cause a fire, and dealers inspect and secure the connection.

Watch for a loose or overheated battery cable connection in the trunk. The recall concerns the cable, not an engine part.

02 SMG transmission (IAIK, shop experience; not an engine item)

IAIK names the SMG transmission as the weak point on these cars, one IAIK expects to give trouble regardless of care, and considers a manual car more reliable.

BMW's parts data, as summarized in our SMG and M DCT gearbox guide, lists the seven-speed SMG in the US E60 M5 and E63 and E64 M6; a US-market manual S85 car is not established there.

Reliability Verdict

Not established yet. The BMW and NHTSA documents we read show no engine recall for the S85. They do not rate how long the engine lasts or how often its bearings wear.

IAIK, from our own shop: the S85 is very solid as long as the maintenance is kept up, and IAIK has not seen one come in with an engine failure. That is IAIK shop experience, not a failure rate.

Power Potential

Not established yet. BMW's factory figure is the only power number given here: 373 kW (500 bhp) at 7,750 rpm.

Cost of Ownership

Not established yet. No BMW document we read gives a service budget, repair cost or replacement mileage for the S85.

Common Questions

What BMW has the S85 engine?

In the US, the S85 is in the E60 M5 sedan built from 09/2005 to 12/2009 and the E63 M6 coupe and E64 M6 convertible built from 2006 to 2010.

How much oil does an S85 take?

BMW's parts catalog lists 9.3 liters of engine oil for the S85. BMW's February 2017 oil bulletin lists BMW M 10W-60 for the S85 in all model years.

How much horsepower does the S85 make?

BMW's US training lists the S85 at 500 bhp (373 kW) at 7,750 rpm and 520 Nm of torque at 6,100 rpm.

Has BMW recalled the S85 for rod bearings?

We did not find a BMW or NHTSA recall, or a BMW service bulletin, about S85 connecting rod bearings. The one M5 and M6 recall we describe above concerns a battery cable, not the engine.

Was the S85 sold in US-market BMWs?

Yes, BMW's US parts catalog lists US-market E60 M5, E63 M6 and E64 M6 types with the S85.

Sources

• BMW M Engines technical training (print date 05/09)
• BMW SI B11 01 15 (February 2017), engine oil quick reference chart
• NHTSA recall record 12V-126
• BMW parts catalog and BMW service information, internal verification, no public link.