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166.991
Engine overview
Manufacturer
MERCEDES-BENZ
Production years
2002-2005
Vehicles with this engine
W414
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
Engine code
166.990
Capacity
1898 cc
Idle speed
750 - 1000 rpm
Normal
13.0 - 17.0 bar
Minimum
11.5 bar
Differential limit between cylinders
1.5 bar
Oil pressure
> 1.0 / 700 > 1.5 / 1000 > 4.0 / 3000 > 4.5 / 5750 bar/rpm
Oil pressure
> 0.8 / 700 > 2.5 / 1000 > 3.0 / 5750 bar/rpm
Engine (petrol)
Fuel system (make and type)
Siemens VDO MSM 2.0
Number of cylinders
4
Firing order
1 - 3 - 4 - 2
Spark plugs (make and type)
Bosch 14 FGH-8 DTURX0 Beru F 8 KTCR
Spark plug gap
1.0 mm
CO exhaust gas
< 0.5 %
CO at fast-idle speed
< 0.3 %
Fast-idle speed
2200 - 2800 rpm
Lambda
0.97 - 1.03
Lambda change (Delta Lambda)
0.03
Oil temperature during test
60 °C
Basic method
MSM (80 - 120) mbar
Alternative method (Germany only)
Nr. 2, 0 ± 25
Cooling system
Cap pressure
1.4 bar
Thermostat opens at
87 - 102 °C
Electrical
Battery
45 Ah
Alternator
90 A
Brakes
Disc thickness, front
22.0 mm
Disc thickness, front, min.
19.4 mm
Disc thickness, rear
8.0 mm
Disc thickness, rear, min.
7.3 mm
Steering and wheel alignment
Toe-out, front
0°07' ± 10' °
Camber, front
1°06' ± 20' °
Castor, front
2°56' ± 30' °
Toe-out, rear
0°55' ± 27' (-> 224208) °
Toe-out, rear
0°18' ± 27' (224209 ->) °
Camber, rear
-2°06' ± 27' °
Wheels and tyres
Tyre size
195/55 R 15 (5.5Jx15)
Optional
195/50 R16 (5.5Jx16)
Optional
185/60 R 15 (5.5Jx15)
Tyre size
185/60 R 15 (5.5Jx15) H2 M+S
Front tyre pressure
2.4 195/55 R 15 2.4 195/50 R16 2.5 185/60 R 15 bar
Front tyre pressure
2.5 bar
Rear tyre pressure
2.0 195/55 R 15 2.3 195/50 R16 2.2 185/60 R 15 bar
Rear tyre pressure
2.6 195/55 R 15 2.6 195/50 R16 2.8 185/60 R 15 bar
Rear tyre pressure
2.8 bar
Capacities
Engine sump, incl. filter
4.5 l
Manual transmission
716.5
Gearbox refill
1.65 l
Automatic transmission
722.7
Gearbox refill
3.3 l
Gearbox refill after overhaul
6.3 l
Cooling system
5.2 l
Cooling system
6.8 l
Air-conditioner refrigerant
600 g
Air-conditioner compressor oil
100 ml
Torque settings
Cylinder head (Torx)
M10 x 183
Oxygen sensor
55 Nm
Spark plugs
25 Nm
Oil plug
30 Nm
Oil filter
25 Nm
Manual transmission drain plug
30 Nm
Wheel nuts
110 Nm
Rear hub
190 Nm
Emissions
Emission code
70/220*2001/1B
Emission standard
Euro 4
CO2 average
197 g/km
CO
0.212 g/km
HC
0.046 g/km
NOx
0.028 g/km
Emission code
70/220*2001/100B
Emission code
70/220*2002/80B
CO2 average
204 g/km
CO
0.445 g/km
HC
0.067 g/km
NOx
0.011 g/km
Workshop procedures for this engine
Step-by-step procedures from the workshop database.
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Who makes these pages, and how TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
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The story behind TorqFix → Workshop data on this page last updated 22 Aug 2026.
