BMW 1989-1995 525i Service Manual page 43

ENGINE-GENERAL
100-1
100 Engine-General
GENERAL
100-1
Cylinder Block and Crankshaft 100-1
Connecting Rods and Pistons . . . . . . . . . . . . . 100· 1
Cylinder Head and Valvetrain 100-2
VANOS (Variable Valve Timing) , 100-2
Lubrication System . . . . . . . . . . . . . . . . . . . . . 100-2
Fuel Supply System . , .. . . . , . . . . . . . . . . . . 100-2
Engine Management System .. . . , . . . , . . . , 100-3
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 100-4
MECHANICAL TROUBLESHOOTING . . . .
100-4
Noise . .. ,. , . . . ... ... .. . ... .. . . .. . . . 100-4
Fluid Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . 100-4
Smoking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100-4
Excessive Oil Consumption . . . . . . . . . . . . . . 100·5
High Fuel Consumption and Low Power 100-5
Engine Not Running 100-5
Compression Test. . . . . . . . . . . . . . . . . . . . . . 100-5
To test compression . . . . . . . . . . . . . . . . . . . . . . 100-5
GENERAL
There are four basic engine configurations used in the s-se-
ries cars covered by this manua l; the 2.5 liter M20 engine. the
2.5 liter M50 engine, the 3.5 liter M30 engine, and the 3.0 and
4.0 liter M60 engines. See Table a.
Cylinder Block and Crankshaft
The cylinde r block contains oilways for the lubrication sys-
tem . All four engine block castings are unique and are not in-
terchangeable.
On 6-cylinde r engines, the cylinder block is cast iron with in-
tegral cylinders that are exposed on all sides to circulating
coolant.
DRIVEABILITY TROUBLESHOOTING
100-8
Warnings and Cautions 100-8
On-Board Diagnostics 100-8
Mechanical Condition 100-11
Carbon Deposits . . , , , 100-11
Preventive Maintenance 100-12
Basic Engine Settings 100-12
Oxygen Sensor 100-12
Air Flow Measurement and Vacuum Leaks . . 100-12
Battery Voltage 100-12
Wiring and Harness Connections 100-13
Ground Connections 100-13
Fuel Supply 100-14
Basic Requirements 100-16
TABLES
a. Engine Specifications 100-1
b. Engine Mechanical Troubleshooting 100·7
c. DME Check Engine Light Fault Codes 100-9
d. Engine Driveability Troubleshooting 100-15
On a-cylinder engines, the cylinder block is cast aluminum
alloy. Instead of stee l cylinder liners, the cylinders have a
"Galnikal" lining. Thi s lining or coating Is created by depositing
a "dispersion layer" of nickel on the alumin um cylinder walls.
The fully counterweighted crankshaft rotates in replaceable
split-shell main bearings. Oilways drilled into the crankshaft pro-
vide bearing lubrication. Flexible lip seals pressed into alloy seal
housings or covers are installed at both ends of the crankshaft.
Connecting Rods and Pistons
The connecting rods use replaceable split-shell bearings at
the crankshaft end and solid bushings at the piston pin end .
The pistons are of the three-ring type with two uppe r compres-
sion rings and a lower one-piece oil scrape r ring. Full·f1oating
piston pins are retained with circlips.
Table a. Engine Specifications
Model
I
Engine code
No.ot
Displacement Compression
I
Horsepower
Torque Ib-It
cylinders liters (cu. in.) ratio SAE net
@
rpm SAE net
@
rpm
16
- - -
525V525iT
1989-1990 M20 2.5 (152.2) 8.8:1 168
@
5.800 164
@
4.300
1991-1992 M50 6 2.5 (152.2) 10.0:1 188
@
5,900 184
@
4.200
1993 on
M50TU (VANOS)
6
2.5 (152.2) 10.5:1 188
@
5,900 184
@
4,200
-
5351 M30 6 3.5 (209.3) 9.0:1 208
@
5,700 225
@
4,000
530i
M60
18
3.0 (182.9)
I
10.5:1
1215
@
5,800
214
@
4.500
I
M60
.
-
540i
18
4.0 (243.1) 10.0:1 1282
@
5,800 295
@
4,500
GENERAL