Engine code
The S50 is BMW M's straight-six for the E36 M3 and, outside the US, the first-generation Z3 M. The name covers three engines whose specifications differ: the European 3.0-liter S50B30, the US-market S50B30US, and the European 3.2-liter S50B32.
BMW's tool documents list S50B30, S50B32, S50US, S52US and S54 as separate engine labels. In US-market cars the 3.0-liter engine was fitted to the E36 M3 Coupe, and BMW's parts catalog lists no US-market S50 in the sedan or convertible.
BMW then used the S52 in the US M3 and in the US Z3 M, and the S52 has its own guide. The 3.2-liter S50B32: Not sold in US-market BMWs, per BMW's own vehicle lists (data to December 2019). BMW's service bulletins describe S50 B32 cars as ECE-market M3 and Z3 M.
Quick read
- Ownership position: Not established yet. We are still researching this engine.
- Reliability: No verdict is established here. The BMW documents we found are service campaigns for specific build windows, not failure rates.
- Cost to own: Not established yet.
- Power potential: Not established yet.
- Main watch item: The throttle and cruise control cable bushing recall, NHTSA campaign 97V131000, which lists the M3 for model years 1995, 1996 and 1997.
S50 At a Glance
| Question | Practical answer |
|---|---|
| Sold in US-market BMWs? | Only the 3.0-liter S50B30US, in the E36 M3 Coupe. European S50B30 and S50B32: Not sold in US-market BMWs, per BMW's own vehicle lists (data to December 2019). |
| Where you find it, US market | E36 M3 Coupe built from 12/1993, with the oil filter element row running to 01/1996. |
| Where you find it, outside the US | European-market types, with catalog dates rather than production claims. 3.0-liter S50B30: M3 Coupe from 03/1992, Convertible from 11/1993 and Sedan from 06/1994, all ending in 1995. 3.2-liter S50B32: M3 Coupe from 03/1995 to 12/1998, Sedan from 02/1995 to 12/1997, Convertible from 10/1995 to 08/1999, Z3 M Roadster from 04/1996 to 06/2000 and Z3 M Coupe from 09/1997 to 07/2000. |
| Factory output, S50B30US | BMW's workshop data gives 176 kW at 6,000 rpm and 305 Nm at 4,250 rpm. |
| Engine oil, S50B30US | 6.5 liters with the filter. |
| Maximum engine speed | S50B30US 6,800 rpm, European S50B30 7,280 rpm and S50B32 7,600 rpm. |
| Reliability profile | Not established yet. We are still researching this engine. |
| Typical annual planning budget | Not established yet. |
Technical Specifications
The three variants are listed together so the US engine can be told apart from the European ones.
| Specification | Detail |
|---|---|
| Configuration | Inline 6 cylinders in all three variants. |
| Displacement | S50B30 and S50B30US 2,990 cc; S50B32 3,201 cc. |
| Bore x stroke | S50B30 and S50B30US 86.0 mm x 85.8 mm; S50B32 86.4 mm x 91.0 mm. |
| Compression ratio | S50B30 10.8:1; S50B30US 10.5:1; S50B32 11.3:1. |
| Compression pressure, minimum | S50B30 10-11 bar; S50B30US 10-11 bar; S50B32 11-12 bar. |
| Output, S50B30US | 176 kW at 6,000 rpm and 305 Nm at 4,250 rpm. |
| Output, European S50B30 | Wikipedia lists 210 kW at 7,000 rpm and 329 Nm at 3,500 rpm. |
| Output, S50B32 | Wikipedia lists 236 kW at 7,400 rpm and 350 Nm at 3,250 rpm. |
| VANOS | BMW's service documents list a VANOS adjustment unit on all three variants. A 1995 BMW special-tool bulletin describes a double VANOS unit for the S50 but does not say which variant. |
| Engine oil capacity | S50B30US 6.5 liters; S50B30 7.0 liters; S50B32 5.5 liters, each with the filter. |
| Engine oil grade | Not established for the S50 by name. BMW's US engine oil chart (SI B11 01 15, February 2017) lists 5W-30 LL01 or 0W-30 LL01FE for all BMW gasoline engines in its model year 2011 and older table, and does not name the S50. |
| Engine management | Not established yet for the S50B30US. We did not find it in a BMW document. |
| Firing order | Not established yet. We did not find it in a document we opened. |
Factory Deep Dive
Why there are two 3.0-liter engines
The S50B30 and the S50B30US share the same bore, stroke and displacement, but BMW's workshop data gives them different compression ratios, power and torque, and different oil capacities.
In BMW's VANOS tightening table, the S50 US is grouped with the M50, M52 and S52, while the European S50 has its own rows.
Variants and markets
Wikipedia says the S50B30US was used only in North American E36 M3 models and was replaced by the S52 from 1996.
BMW's parts catalog lists the US M3 Coupe with the S52 from 04/1996, the Sedan from 09/1996 and the Convertible from 03/1998.
Service Parts at a Glance
Part numbers below are for the US-market S50B30US and are current as of BMW's parts data dated 12/2019. Check fitment by VIN before ordering.
| Part | BMW part number | Note |
|---|---|---|
| Oil filter element set | 11 42 7 833 769 | Listed for the US E36 M3 Coupe; the same number is listed for the S52 and S54. |
| Spark plugs | 12 12 9 063 428 and 12 12 9 064 619 | BMW's catalog lists both for the US M3 Coupe, quantity 6 each; confirm which fits by VIN. |
| Ignition coil | 12 13 7 599 218 | Current number; it replaces 12 13 9 066 468, which BMW discontinued in 08/2011. Quantity 6. |
| Water pump | 11 51 7 527 799 | Mechanical pump, also listed for the S52. |
| Thermostat | 11 53 7 511 083 (92 C) and 11 53 7 511 580 (88 C) | BMW's catalog lists both for the US M3 Coupe, so confirm by VIN. |
| Air filter element | 13 72 1 730 449 | It replaces 13 72 1 730 946, discontinued in 11/2013. |
| Cylinder head cover | 11 12 1 738 410 | Listed for the US M3 Coupe; the same cover is also listed for US cars with the M50. |
| Cylinder head gasket set (profile gaskets) | 11 12 0 034 107 | Listed for the US M3 Coupe built to 09/1995. |
Known Failure Points and Service Items
Only items backed by a BMW service bulletin or a recall are listed. Whether a specific car is covered is a VIN check with BMW.
01 Throttle and cruise control cable bushing (recall 97V131000)
Under NHTSA recall 97V131000, the throttle cable and the cruise control cable share one lever at the throttle housing, and the plastic bushing on either cable may crack. NHTSA says a broken bushing could leave the throttle partly open so the car might not slow as expected, and that dealers install a spring steel clip on each cable.
NHTSA lists the M3 for model years 1995, 1996 and 1997 under this recall. BMW's service bulletin 00 35 05 01/0797 covers the same cable problem and lists the E36 S50 US built 11/92 to 09/95 and the E36 S52 US built 10/95 to 06/97.
Watch for: a throttle that is slow to close or an accelerator pedal that feels like it sticks. Check that the cable clips are fitted.
02 Cooling system warning (recall 98V178000)
NHTSA recall 98V178000 says a failed coolant system part such as the thermostat, water pump or fan belt can raise coolant temperature and pressure sharply. The remedy was a new radiator cap design to control pressure and give more coolant overflow, and NHTSA lists the M3 under model year 1995.
The notice does not name engines, so treat it as a vehicle recall that includes the M3, not as an S50 defect.
Watch for: coolant temperature warnings. A cooling fault on this engine deserves attention before the car is driven further.
03 Valve train rattle after a cold start
BMW's service bulletin 11 10 98 (367) lists the US E36 S50 (written S50U in the bulletin) and the E36 S52 among the engines it covers, and says a rattle right after a cold start is what most often leads to hydraulic lifters being replaced. BMW puts the noise down to thick cold oil, says it does not shorten engine life, and asks for the bulletin's checks only when a customer complains.
Watch for: a short rattle just after a cold start that fades as the oil warms.
04 Non-US cars only: VANOS service campaigns on the S50B32
BMW's service bulletin 00 11 14 01/1097 covers E36 S50 B32 ECE cars built 06/1997 to 09/1997 whose VANOS unit had an unhardened needle bearing on the pump. BMW says a failed bearing can put metal particles into the engine oil and lower torque by as much as 30 percent.
BMW's service bulletin 00 11 49 01/0300 covers E36 S50 B32 ECE cars built up to 10/1999 where the VANOS cap screws on the exhaust-side solenoid valves can crack from vibration, and says a lifted cap can then lose a lot of oil fast.
These apply to European-market cars. Watch for: a drop in output with noise from the VANOS unit, or sudden oil loss.
Reliability Verdict
Not established yet. We are still researching this engine.
Power Potential
Not established yet. We are still researching this engine.
Cost of Ownership
Not established yet. We are still researching this engine.
Common Questions
What BMW has the S50 engine?
The S50 powered the E36 M3 and, in non-US markets, the Z3 M; US-market Z3 M cars have the S52 and later the S54.
What is the difference between the S50B30US and the European S50B30?
Both are 2,990 cc with 86.0 mm x 85.8 mm bore and stroke, but the S50B30US has a 10.5:1 compression ratio and takes 6.5 liters of oil, while the European S50B30 has 10.8:1 and takes 7.0 liters.
Did the US get the S50B32?
No. The 3.2-liter S50B32: Not sold in US-market BMWs, per BMW's own vehicle lists (data to December 2019). BMW's parts catalog lists the US M3 3.2 and Z3 M with the S52.
How much oil does an S50 take?
BMW's workshop data gives 6.5 liters for the S50B30US, 7.0 liters for the European S50B30 and 5.5 liters for the S50B32, each with the filter.
What is the maximum engine speed of the S50?
BMW's workshop data gives 6,800 rpm for the S50B30US, 7,280 rpm for the European S50B30 and 7,600 rpm for the S50B32.
Did every US E36 M3 have the S50?
No. BMW's parts catalog lists the S50B30US only in the US M3 Coupe built from 12/1993, and lists the US M3 Coupe with the S52 from 04/1996.
Sources
- BMW workshop technical data for the S50B30, S50B30US and S50B32 (engine data, oil supply).
- BMW Service Information 00 35 05 01/0797, gas and cruise control Bowden cable, US models.
- BMW Service Information 11 10 98 (367), rattling noises from the valve timing gear.
- BMW Service Information 00 11 14 01/1097, VANOS adjustment unit needle bearing, E36 S50 B32 ECE.
- BMW Service Information 00 11 49 01/0300, VANOS cap screw connection, E36 S50 B32.
- BMW parts catalog data, dated 12/2019, for fitment, build months and part number supersession.
- BMW SI B11 01 15 (Feb 2017), engine oil chart
- NHTSA recall record 97V131000
- NHTSA recall record 98V178000
- Wikipedia, BMW S50 (outputs for the European engines and cross-checks only)
