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Engine code

IA Technical Bulletin

BMW M30 Engine Guide

Engine: M30

Bulletin text

The M30 is a SOHC straight-six petrol engine that Wikipedia says BMW built from 1968 to 1995, which it calls BMW's longest produced engine. Wikipedia says it first appeared in the 2500 and 2800 sedans and the 2800 CS coupe in 1968, and that the M30 began to be phased out after the M50 arrived in 1990.

BMW sold the M30 in US-market cars. BMW's parts data lists it in 20 US models across the E3, E9, E12, E23, E24, E28, E32 and E34 chassis, built from 01/1969 to 02/1993.

Wikipedia lists six displacements for the M30, from 2,494 cc to 3,430 cc. A statement about the M30 only holds for the version in a given car. This guide says which version each statement applies to, and where we cannot tell, it says so.

Quick read

Ownership position: Not established yet. We are still researching this engine.
Reliability: Not established yet. We are still researching this engine.
Cost to own: Not established yet. We are still researching this engine.
Power potential: Not established yet. We are still researching this engine. Factory outputs Wikipedia lists are in Technical Specifications.
Main watch item: Not established yet. The cooling system recall under Known Failure Points is the only BMW-backed item we found.

M30 At a Glance

Question	Practical answer
Sold in US-market BMWs	Yes. BMW's parts data lists the M30 in 20 US models from the 2500 to the E34 535i.
Years built	Wikipedia says 1968-1995 worldwide. US-market cars in BMW's parts data were built from 01/1969 to 02/1993.
Layout	SOHC straight-six petrol with a cast iron block, an aluminum alloy head, two valves per cylinder and a chain-driven camshaft, according to Wikipedia.
Versions	Wikipedia names the versions M30B25, M30B28, M30B30, M30B32, M30B33, M30B34 and M30B35, with a V suffix on the carbureted ones.
Engine oil capacity	BMW's fill-quantity data lists 5.75 liters (about 6.1 US quarts) for the US 635CSi, E28 535i, E32 735i, E32 735iL and E34 535i. The other US M30 cars are not established.
Reliability profile	Not established yet. We are still researching this engine.
Before buying	Confirm the exact version, because Wikipedia lists different US outputs for the 3.0, 3.2 and 3.4 liter versions.

Where you find it

BMW's parts data (the data we hold ends in December 2019) lists these US-market cars with the M30. Dates are BMW build dates.

US model	Built
E3 2500	01/1969-07/1970
E3 2800	06/1969-10/1970
E3 2800Bav	12/1970-07/1971
E3 3.0SBav	07/1971-07/1974
E3 3.0S	09/1973-07/1974
E3 3.0Si	09/1974-07/1976
E9 2800CS	08/1969-03/1971
E9 3.0CS	04/1971-12/1974
E12 530i	10/1974-08/1978
E12 528i	07/1978-07/1981
E24 630CSi	09/1976-09/1977
E24 633CSi	01/1978-09/1984
E24 635CSi	10/1984-04/1989
E23 733i	12/1977-09/1984
E23 735i	10/1984-06/1986
E28 533i	09/1982-09/1984
E28 535i	10/1984-12/1987
E32 735i	12/1986-06/1992
E32 735iL	04/1988-07/1992
E34 535i	06/1988-02/1993

Technical Specifications

Specification	Detail
Configuration	SOHC straight-six petrol, two valves per cylinder, rocker arm valve actuation
Block and head	Cast iron block, aluminum alloy head, forged crankshaft
Camshaft drive	Chain
Slant	30 degrees to the right, shared with the M10
Engine management	Per Wikipedia: carburetors on the V versions; Bosch D-Jetronic on the first fuel-injected M30B30, later Bosch L-Jetronic; Bosch Motronic on the M30B34 and M30B35, and on the US M30B32 from June 1981
Engine oil	5.75 liters for the US cars named in At a Glance. BMW of North America's oil chart (SI B11 01 15, February 2017) lists 5W-30 LL01 or 0W-30 LL01FE for all BMW gasoline engines of model year 2011 and older; it does not name the M30 by code.
Firing order	1-5-3-6-2-4, per BMW's Engine Technology training chart
Coolant	Not established yet.

Versions, as listed by Wikipedia (all markets)

Version	Displacement, bore x stroke	Output
M30B25V	2,494 cc, 86 x 71.6 mm	150 PS at 6,000 rpm, 211 Nm at 3,700 rpm (1968)
M30B28	2,788 cc, 86 x 80 mm	135 kW at 5,800 rpm, 240 Nm at 4,200 rpm (1977)
M30B30	2,986 cc, 3 mm more bore than the 2,788 cc version	200 PS at 5,500 rpm, 272 Nm at 4,300 rpm (1971)
M30B32	3,210 cc, 89 x 86 mm	200 PS at 5,500 rpm, 285 Nm at 4,300 rpm (1976)
M30B34	3,430 cc, 92 x 86 mm	160 kW at 5,800 rpm, 310 Nm at 4,200 rpm (1982)
M30B35	3,430 cc	155 kW at 5,700 rpm, 305 Nm at 4,000 rpm (1988)

US-market notes from Wikipedia

The M30B34 in North America used 8.0:1 compression and produced 185 PS.
The M30B32 in USA spec is listed at 128-130 kW in the 633CSi and 130-145 kW in the 733i, and Wikipedia says the US version changed from L-Jetronic to Motronic in June 1981.
The M30B30 is listed for North America only at 131 kW in the 1975-1978 530i and 129 kW in the 1977-1978 630CSi.
The carbureted M30B30V in United States trim is listed at 170 hp at 5,800 rpm.

Wikipedia lists the E34 535i, E32 735i and 1988-1989 635CSi with the M30B35, but BMW's fill-quantity data labels the US cars of those types M30 B34, so we do not give a version code for them.

Factory Deep Dive

Block, head and layout

Wikipedia describes a cast iron block with an aluminum head and a forged crankshaft. It says the M30 was developed in the late 1960s, loosely based on the M10 four-cylinder, and shares its 30 degree slant, crossflow head and chain-driven camshaft with rocker arms.

Version names

Wikipedia says the V in names like M30B28V stands for Vergaser, the German word for carburetor. It adds that the early engines were called M06 and M68 until all versions used the M30 prefix in 1981.

Fuel injection

Wikipedia says Bosch L-Jetronic fuel injection was added to the 2,788 cc version in 1977. It says the M30B34 used Bosch Motronic in all markets.

Relatives

Wikipedia says the M30 was the basis for the turbocharged M102 and M106 engines and that the 745i used them. Those engines are not in BMW's US parts data under the M30 label.

Service Parts at a Glance

These numbers come from BMW's US parts data (December 2019). Most parts below fit only some M30 models. Dates are BMW build dates. Check the exact car before ordering.

Part	BMW part number	Note
Oil filter insert	11421256714	Fits the E3 (2500, 2800, 2800Bav, 3.0S, 3.0SBav, 3.0Si), E9 (2800CS, 3.0CS), E12 530i (10/1974-09/1977) and E24 630CSi (09/1976-09/1977).
Thermostat	11531710953	Fits the E3, E9, E23, E24, E28, E32 and E34 M30 models, but is not listed for the E12 528i or 530i.
Exchange water pump	11519070756	Fits the E3, E9, E12 (528i, 530i), 630CSi, 633CSi and 733i, with builds ending 09/1979 for the 633CSi and 733i. Several rows carry an 'only in conjunction with' condition.
Spark plug, Bosch W7DC	12129062594	Fits the E3 and E9 models, six per engine in most rows.
Spark plug, Bosch WR9LS	12121279599	Six per engine. Fits the E28 533i (09/1982-01/1984) and 535i (10/1984-12/1987), E24 633CSi (01/1978-09/1984) and 635CSi (10/1984-04/1989), and E23 733i (12/1977-09/1984) and 735i (10/1984-06/1986).
Spark plug, Bosch WR9DS	12121272128	Six per engine. Fits the E12 528i (09/1979-07/1981).
Ignition coil	12131357294	Fits the E3, E9, E12 530i (10/1974-08/1978) and E24 630CSi (09/1976-09/1977).
Ignition coil	12131286087	Fits the E28 533i (01/1984-09/1984) and 535i (10/1984-12/1987), E24 633CSi (01/1984-09/1984) and 635CSi (10/1984-04/1989), E23 733i (01/1984-09/1984) and 735i (10/1984-06/1986), and E32 735i (12/1986-09/1987).
Fuel filter	13321256425	Fits the E9 3.0CS (04/1971-12/1974), E3 3.0SBav and 3.0Si, E12 530i (09/1976-08/1978), E24 630CSi and 633CSi (01/1978-09/1978), and E23 733i (12/1977-09/1984).
Air filter element	13721278138	Fits the E3 3.0Si, E12 528i (09/1979-07/1981), E28 533i and 535i, E24 630CSi, 633CSi and 635CSi, and E23 733i and 735i.

Known Failure Points and Service Items

Not established yet. We found no BMW service bulletin or training document for the M30.

01 Cooling system, 535i and 735i

NHTSA recall 98V-178 was received on 4 August 1998 and lists the 535i for model years 1989-1995 and the 735i and 735iL for 1988-1995. BMW's parts data lists the US E34 535i with the M30 for cars built up to 02/1993, and the E32 735i and 735iL up to 06/1992 and 07/1992. The record does not name an engine. The record says a failure of a coolant system component such as the thermostat, water pump or fan belt can raise coolant temperature and pressure. The remedy was a new design radiator cap.

Watch for: an overheating indication. The record's stated consequence is that hot coolant could be expelled if a heater core end piece cracked. NHTSA lists vehicles by model and model year, not by engine, and we cannot say whether a given car had the remedy done.

NHTSA's recall lookup returned no records for the 1973 3.0CS, 1976 530i, 1977 630CSi, 1980 528i, 1983 733i, 1983 633CSi and 1987 535i. That is a sample check, not a complete search.

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

Which US-market BMWs had the M30 engine?

BMW's parts data lists the M30 in 20 US models: in the E3 (2500, 2800, 2800Bav, 3.0S, 3.0SBav, 3.0Si), E9 (2800CS, 3.0CS), E12 (528i, 530i), E24 (630CSi, 633CSi, 635CSi), E23 (733i, 735i), E28 (533i, 535i), E32 (735i, 735iL) and E34 (535i).

Does the M30 have a timing belt or a timing chain?

Wikipedia describes the M30 camshaft as chain-driven, unlike the M20, which uses a timing belt.

How much oil does an M30 take?

BMW's fill-quantity data lists 5.75 liters, about 6.1 US quarts, for the US 635CSi, E28 535i, E32 735i, E32 735iL and E34 535i. Other US M30 cars are not established.

What is the difference between the M30 and the M20?

Wikipedia says the M30 is the larger six that stayed in production alongside the M20, and that the M20 differs by using a timing belt, 91 mm bore spacing and a 20 degree slant.