BMW 6 Series E24 Specs and Maintenance: Every Engine From the 630CS to the M6
The E24 ran from January 1976 to April 1989, with 86,216 cars built, and every one of them is a 2-door coupe on a 2,630 mm wheelbase. Length is 4,755 mm (4,923 mm for US cars, the gain coming from the 5-mph bumpers), width 1,725 mm, height 1,365 mm. Curb weight runs 1,450–1,619 kg, US cars heavier because of the bumpers, with a 70 L fuel tank and a 415 L boot. Layout is front engine, rear-wheel drive, with MacPherson struts up front, independent semi-trailing arms at the rear, and recirculating-ball power steering. The E24 guide's spec table covers every model; this page pulls it together with the service schedule the guide carries.
The engines, model by model
| Model | Engine | Output | Years |
|---|---|---|---|
| 630CS (Euro) | M30B30V 2,986 cc SOHC I6, carburetted | 185 PS @ 5,800 rpm, 255 Nm @ 3,500 rpm | 1976–79 |
| 628CSi | M30B28 2,788 cc SOHC I6 | 184 PS @ 5,800 rpm, 235 Nm @ 4,200 rpm | 1979–87 |
| 633CSi | M30B32 3,210 cc SOHC I6 | 200 PS (1976–79) / 197 PS (1979–84) | 1976–84 |
| 635CSi | M90 3,453 cc SOHC I6 | 218 PS @ 5,200 rpm, 304 Nm @ 4,000 rpm | 1978–82 |
| 635CSi (Euro) | M30B34 3,430 cc SOHC I6 | 218 PS @ 5,500 rpm, 310 Nm @ 4,000 rpm; 0–62 mph 7.4 s, 142 mph | 1982–87 |
| 635CSi (US) | M30B34 3,430 cc, catalysed | 182 hp @ 5,400 rpm, 290 Nm (214 lb-ft) @ 4,000 rpm | 1985–87 |
| 635CSi (Euro) | M30B35 3,430 cc, higher compression | 220 PS @ 5,700 rpm, 310 Nm @ 4,000 rpm; US catalysed 208 hp, 305 Nm | 1987–89 |
| M635CSi (Euro) | M88/3 3,453 cc DOHC I6, M1-derived | 286 PS @ 6,500 rpm, 340 Nm @ 4,500 rpm | 1984–89 |
| M6 (US) | S38B35 3,453 cc DOHC I6 | 256 hp @ 6,500 rpm, 329 Nm @ 4,500 rpm; 9.8:1 compression, catalytic converter, double-row timing chain | 1987–89 |
US cars differ from the Euro cars in the details that matter when buying: the US got a fuel-injected 630CSi at 176 hp instead of the carburetted Euro 630CS, and the US 633CSi ran 181 hp falling to 174 hp, then back to 181 hp in 1982–84. The early 635CSi with the M90 came standard with a close-ratio 5-speed and a black rear spoiler, and it was Germany's fastest 4-seater of its day. The M30B34 is a smaller bore with a longer stroke than the M90. The 1982 635CSi does 0–100 km/h in 7.4 s with a 229 km/h (142 mph) top speed and about 10.6 L/100 km combined; the automatic version is about 9.0 s to 62 mph. On the track, the E24 took ETC titles in 1981, 1983, and 1986, the DTM in 1984, and the Australian Touring Car Championship in 1985, with about 50 Group A competition chassis built in 1983–85.
Gearboxes, brakes, and wheels
Gearboxes are the Getrag 262 4-speed manual, the Getrag 265 5-speed manual, the ZF 3HP22 3-speed automatic, and the ZF 4HP22 4-speed automatic from 1983. Manuals are rare and desirable; most 635CSis are automatics. The 1982 facelift brought a wide-ratio 5-speed or a 4-speed automatic option, and the 4-speed ZF replaced the 3-speed in 1983, with EH electronic control phased in late in the year — note that the EH gearbox wiring plug differs from 5/7 Series units.
Brakes: the 635CSi runs 300 mm ventilated front discs, uprated for the M cars, and the M635CSi has cross-vented discs with ATE four-pot calipers and standard ABS. Rear discs were ventilated before 1982 and solid after the facelift — the guide calls the ventilated rears a needless complication. ABS was optional from 1979 and standard on the M635CSi. A documented upgrade path is E32 7 Series Brembo front discs and calipers fitted to M635CSi cars. From 1988, self-levelling rear suspension joined the 635CSi and M6 options list, which affects rear brake and suspension servicing.
Wheels are the E24's famous trap: most cars sit on metric TRX 390 mm rims (415 mm on most M635CSi cars), and no inch-size tyre fits a metric rim. Michelin Classic still lists TRX sizes at classic-tyre prices — owners report about GBP 400 per TRX tyre, as listed in the guide — but old TRX rubber is a safety issue regardless of tread. The practical advice is to store the metric wheels and fit conventional 15, 16, or 17-inch wheels for driving, avoiding very low-profile tyres the chassis was not designed for. The M635CSi also came with 16-inch BBS 3-piece wheels. Wheel bolts are the 5-lug BMW pattern shared with contemporary 5/7 Series cars; verify hub bore and offset when fitting E28, E23, or E32 wheels and test-fit before buying.
The M30 service schedule
- Engine oil + filter: 7,500 miles under BMW's guidance for pre-1991 cars, and at least annually. Many owners run 5,000-mile changes on old M30s; use quality oil and an OEM-type filter.
- Valve lash: check at each Inspection service. The M30 uses mechanical tappets with no hydraulic lifters, so a noisy top end can also mean loose oil spray bar banjo bolts — check those first.
- Coolant: flush and replace on purchase of any unknown-history car, then per the Inspection schedule. A blocked or aged radiator causes overheating and warped heads on M30s.
- All fluids on purchase: owner advice is to change everything on buying an unknown car — ATF, brakes, gearbox, engine, final drive, and coolant — plus a strong dose of fuel-system cleaner.
- Spark plugs: per the Inspection schedule, in original-spec Bosch. Uneven running is usually the idle valve, not the plugs — clean the idle valve first.
- Transmission fluid (auto): with the fluid change on purchase, then per schedule. On the 4HP22, never rev in N/P; long idling ruins the front drive clutch.
- Differential oil: with the fluid change on purchase, then per schedule. Check LSD function — both wheels turn the same direction when spun — and the ratio tag.
- Air filter / fuel filter: per the Inspection schedule; cheap insurance on a 40-year-old injection system.
- Annual rust inspection: every pre-winter, and keep the sunroof and door drains clear.
- Timing chain (M30): chain-driven with no belt interval — chain replacement is not a routine service item like a belt. That is the contrast with the M cars below.
The M cars: the timing chain is the service item
On the M88/S38, the timing chain is replaced every 100,000 miles or 10 years, and it is the M cars' only major engine concern — with no symptom until failure, which is catastrophic. No service-history evidence means budgeting the job. The M30, by contrast, uses a timing chain with no routine replacement interval. One more M-car note from the guide: the M635CSi's Bilstein suspension, deeper air dam, and 16-inch BBS 3-piece wheels arrived with the car at its Frankfurt 1983 launch, and the US M6 came standard with heated power seats, self-levelling rear suspension, a rear-seat drinks chiller, and 8-speaker premium audio.
Parts interchange: the E28 is the donor
Pre-1982 Series 1 cars share E12 5 Series running gear, and facelift cars from 1982 share E28 5 Series suspension, electronics, and interior parts. Gearboxes (Getrag 265/260, ZF 4HP22), differentials (2.93, 3.25, and 3.91 ratios), and control arms all interchange with the E28, which is the plentiful donor for manual conversions — except that the EH gearbox wiring plug differs. M30 engines interchange across the E12, E28, E23, E32, and E34 family, and the late M30B35 from the E32 735i is the natural upgrade. A turbo swap is documented too: the E23 745i M102/M106 engine running at 7 psi boost. Headlamps from 1987 interchange with E32 7 Series ellipsoid units, and M635CSi and M6 cars share Recaro-style sport seats and the M steering wheel with the E28 M5 family. For deeper reading, the guide's How-To Links tab points to Wikipedia's full E24 history, the Hagerty UK and Drive-My buying guides, Classics World, the Unixnerd owner's page, the Big Coupe forum, the BMW Car Club GB 6 Series register, Sharkfest, Ate Up With Motor's history, Munich Legends' M635CSi project, and the E28 Goodies guide to buying an LSD.
What this page does not cover: torque figures for individual service items, fluid capacities, and part numbers for consumables. The guide's tabs do not state those, so they are left out rather than guessed. If a workshop manual contradicts anything here, the manual and your car's actual configuration win.
Open the full interactive BMW 6 Series E24 guide for the complete stock specs, engine maintenance schedule, common fixes, and how-to links.
Compiled from the Cerch Garage BMW 6 Series E24 guide (Stock Specs, Engine Maintenance, Brakes, Tires and Wheels, Differentials, Parts Interchange, Year Differences, and How-To Links tabs), which draws on Wikipedia, Drive-My, PistonHeads, Hagerty UK, and owner-community sources as cited in the guide. Prices are as listed in the guide (tabs dated Oct 27, 2026) and change; verify before buying anything.