The 2.4-liter BMW M21 or M21D24 diesel engine was produced from 1983 to 1991 and was installed on the concern’s popular models: 3-Series in the back of the E30 and 5-Series in the back of the E28 and E34. This unit was offered both in an atmospheric version and in a turbocharged version.
Specifications
| Production years | 1983-1991 |
| Displacement, cc | 2443 |
| Fuel system | vortex chamber |
| Power output, hp | 86 (M21D24 or M21D24S) 115 (M21D24 Turbo or M21D24T) |
| Torque output, Nm | 152 (M21D24S) 210 – 220 (M21D24T) |
| Cylinder block | cast iron R6 |
| Block head | aluminum 12v |
| Cylinder bore, mm | 80 |
| Piston stroke, mm | 81 |
| Compression ratio | 22.0 |
| Features | no |
| Hydraulic lifters | no |
| Timing drive | belt |
| Phase regulator | no |
| Turbocharging | no (M21D24S) Garrett T3 (M21D24T) |
| Recommended engine oil | 5W-40 |
| Engine oil capacity, liter | 5.5 (M21D24S) 5.75 (M21D24T) |
| Fuel type | diesel |
| Euro standards | EURO 0 |
| Fuel consumption, L/100 km (for BMW 524td 1986) — city — highway — combined |
9.5 5.8 7.1 |
| Engine lifespan, km | ~350 000 |
| Weight, kg | 194 |
The engine was installed on:
- BMW 3-Series E30 in 1985 – 1991;
- BMW 5-Series E28 in 1983 – 1987, 5-Series E34 in 1988 – 1991;
- Lincoln Continental Mark VII in 1984 – 1985.
Disadvantages of the M21D24 engine
- This diesel engine does not tolerate prolonged overheating, cylinder head cracks appear;
- The engine does not start when the glow plug control unit fails;
- Often, the oil supply hoses to the radiator crack and the lubricant pressure drops;
- Monitor the condition of the timing belt, it stretches, jumps and the phases go astray;
- Sometimes there are involuntary starter engagements while driving in traffic jams.
Frequently asked questions about the BMW M21D24
How much power does the BMW M21D24 make?
Power output of the BMW M21D24, hp: 86 (M21D24 or M21D24S); 115 (M21D24 Turbo or M21D24T). Torque, Nm: 152 (M21D24S); 210 - 220 (M21D24T).
How much oil does the BMW M21D24 take and which one?
Engine oil capacity: 5.5 (M21D24S); 5.75 (M21D24T) liters. Recommended oil: 5W-40.
Does the BMW M21D24 have a timing belt or chain?
The BMW M21D24 uses a timing belt.
Is the BMW M21D24 turbocharged?
Yes, the BMW M21D24 is turbocharged (no (M21D24S); Garrett T3 (M21D24T)).
Does the BMW M21D24 need valve clearance adjustment?
Yes, there are no hydraulic lifters, so the valve clearances have to be checked and adjusted periodically.
How long does the BMW M21D24 last?
The typical lifespan of the BMW M21D24 is ~350 000 km with proper maintenance.
What is the fuel consumption of the BMW M21D24?
BMW 524td 1986: city 9.5, highway 5.8, combined 7.1 L/100 km.
What cars was the BMW M21D24 installed on?
BMW 3-Series E30 in 1985 - 1991; BMW 5-Series E28 in 1983 - 1987, 5-Series E34 in 1988 - 1991; Lincoln Continental Mark VII in 1984 - 1985.
What are the common problems of the BMW M21D24?
This diesel engine does not tolerate prolonged overheating, cylinder head cracks appear. The engine does not start when the glow plug control unit fails. All known problems.
