Fuel System - Tightening Torques (n54)

13 71 Air intake silencer

	Type	Thread	Measure
1AZ Clean-air gaiter to throttle valve	N52K	Hose clamp	3 Nm
2AZ Gaiter to intake muffler	N52K	Hose clamp	3 Nm
3AZ Intake silencer to body	N52K	M6	8 Nm
4AZ Intake duct to front wall	N52K/N54	Self-tapping screw	2 Nm
5AZ Air duct to air silencer	N54	Hose clamp	3 Nm
6AZ Air duct to crankcase	N54	M6	9 Nm
7AZ Charge-air duct to bracket	N54	M6	9 Nm
8AZ Air duct, compressor to basic engine	N54	M6	9 Nm
9AZ Pressure sensor to charge-air duct	N54	M6	2 Nm
10AZ Engine sound system to charge-air duct	N54	Hose clamp	3 Nm
11AZ Engine sound line to sound system	N54	Hose clamp	3 Nm
12AZ Holder for air duct to cylinder head	N54	M6	9 Nm
13AZ Air intake hose to throttle valve assembly	N52K	Hose clamp	3 Nm

TIGHTENING TORQUE SPECIFICATION - AIR INTAKE SILENCER

	Type	Measure
1AZ Carburetor to intake manifold	M10/M20/M30	10 Nm
2AZ Carburetor to insulating flange	M10/M20/M30	10 Nm
3AZ Insulating flange to intake manifold	M10/M20/M30	10 Nm
4AZ Idling shut off valve; max.	M10/M20/M30	5 Nm
5AZ Flow valve; max.	M10/M20/M30	28 Nm
6AZ Throttle valve assembly to float housing; max.	M10/M20/M30	9 Nm
8AZ Throttle valve control to carburetor; max.	2BE	3 Nm
9AZ Warm-up regulator to engine	M10/M20/M30	23 Nm

TIGHTENING TORQUE SPECIFICATION - CARBURETOR

	Type	Thread	Measure
1AZ Fuel line to filter housing and injection pump
Coupling nut	M21/M51/M41	M14 x 1.5	14 Nm
Adapter	M21/M51/M41	M12 x 1.5	9 Nm
Hollow bolt	M21/M51/M41	M14 x 1.5	14 Nm
2AZ Fuel filter to holder	M51/M41	M8	22 Nm
3AZ Air duct to fuel cooler	M47		5.7 Nm
	M57		2 Nm
4AZ Fuel filter cover	M47		25 Nm
5AZ Fuel filter with holder to body	N42		8.8 Nm

TIGHTENING TORQUE SPECIFICATION - FUEL FILTER

	Type	Thread	Tightening specification	Measure
1AZ Rail, high-pressure side, to cylinder head	N54	M7 x 16		13 ± 2 Nm
2AZ High-pressure line to cylinder head	N54	M7 x 16		13 ± 2 Nm
3AZ High-pressure fuel sensor	N54	M10		30 Nm
4AZ Low pressure fuel sensor	N54	M10		20 Nm
5AZ Hold-down device to cylinder head	N54	M7 x 20		13 ± 2 Nm
6AZ Feed line to high-pressure pump	N54	M14	Coat screw connection with transmission oil	30 Nm
7AZ High-pressure line to rail and high-pressure pump	N54	M14	Coat screw connection with transmission oil	30 ± 3 Nm
8AZ High-pressure lines to rail and injector	N54	M12	Coat screw connection with transmission oil	23±3 Nm
9AZ Fuel delivery line	N54	M8 x 17	Replace screw
			1. Tightening	10 Nm
			2. Angle-of-rotation tightening	90° ± 15°
10AZ Bracket, fuel line, to engine support frame	N54	M6 x 12		8 Nm

TIGHTENING TORQUE SPECIFICATION - FUEL INJECTION NOZZLES AND PIPES

	Type	Thread	Tightening specification	Measure
1AZ Fuel injector to intake manifold	All	M6		10 Nm
2AZ Coupling nut on fuel injector	All/with K-Jetr.			25 Nm

TIGHTENING TORQUE SPECIFICATION - FUEL INJECTORS

	Type	Thread	Measure
1AZ Fuel pump to engine	All		12 Nm
2AZ Fuel pipe coupling bolt	All/with K-Jetr.	M8	9 Nm
3AZ Fuel pipe coupling bolt	All/with K-Jetr.	M12	20 Nm
4AZ Fuel pipe to pressure regulator	All/with L-Jetr.		30 Nm
5AZ Return pipe connector to pressure regulator	All/with L-Jetr.		27 Nm

TIGHTENING TORQUE SPECIFICATION - FUEL PUMP WITH DRIVE AND PIPES

	Type	Measure
1AZ Plug for high pressure section of injection pump	M21/M51/M41	25 Nm
2AZ Distributor injection pump to holder	M21/M51/M41	25 Nm
3AZ Electric shutoff to injection pump	M21/M51/M41	20 ± 5 Nm
4AZ Electric cold start valve to injection pump	M21	20 Nm
5AZ Coupling bolt (OUT) to injection pump (fuel return)	M21/M51/M41	25 Nm
6AZ Pressure valve holder to injection pump	M21/M51	45 Nm
7AZ Expansion element housing (temperature dependent idling speed boost) to injection pump	M21	18 Nm
8AZ Distributor injection pump to flange and console	M21/M51/M41	22 Nm
9AZ Electr. line on fuel cutout device	M51/M41	2.5 Nm
10AZ Fuel feed line to injection pump (VP44)	M47	30 Nm
11AZ Fuel return line to injection pump (VP44)	M47	25 Nm
12AZ Plug for static basic adjustment (injection pump VP44)	M47	13 Nm
13AZ Blocking screw for injection pump shaft without spacer plate (injection pump VP44)	M47	31 Nm
14AZ Blocking screw for injection pump shaft with spacer plate (injection pump VP44)	M47	13 Nm
15AZ Injection line (union nut) to injection pump (VP44)	M47	30 Nm

TIGHTENING TORQUE SPECIFICATION - INJECTION PUMP, CONTROL RECEPTACLE

	Type	Thread	Tightening specification	Measure
1AZ High-pressure fuel pump to vacuum pump	N54, N53	M6x25		9 Nm

TIGHTENING TORQUE SPECIFICATION - INJECTION PUMP, CONTROL

	Type	Thread	Measure
1AZ Coolant temperature sensor	N54	M12x1.5	13.5 Nm
2AZ Intake pressure sensor	N54	K50x16	3.75 Nm
3AZ Camshaft sensor to cylinder head	N54	M6x16	8 Nm
4AZ Crankshaft sensor to crankcase	N54	M6x16	8 Nm
5AZ Knock sensor to crankcase	N54	M8x30	21.5 Nm

TIGHTENING TORQUE SPECIFICATION - SENDERS FOR CONTROL UNIT

	Type	Measure
1AZ Temperature time switch	M21/M51	18 Nm
2AZ Temperature sensor, water	M60/1/M60/2/M21/M51	18 Nm
2AZ Temperature sensor, water	All others	13 Nm
3AZ Temperature switch	All	28 Nm
4AZ Temperature sensor, air	All	13 Nm
5AZ Charge-air pressure sensor to bracket	M51/M41	4 Nm
Charge-air pressure sensor to intake manifold	M47	5 Nm
6AZ Dual temperature sensor (4-pin plug connection)	M41/M43/M44/S50/S52/M52/M57/M67/M62/M73	13 Nm
7AZ Air-mass sensor on lower section of intake filter housing	M51	3.5 Nm
Air-mass flow sensor to cylinder head cover	M47/M47TU/M57/M57TU/M57T2	4.5 Nm
8AZ Pulse generator, camshaft to cylinder head cover	M57	4.5 Nm
	M47TU/M57TU	3.5 Nm
	M57T2	2.3 Nm
9AZ Intake neck on air-mass flow sensor	M47	9 Nm

TIGHTENING TORQUE SPECIFICATION - SENDERS FOR CONTROL UNIT

	Type	Thread	Tightening specification	Measure
1AZ Throttle-valve assembly to intake manifold	N54	M6 x 50		8 Nm

TIGHTENING TORQUE SPECIFICATION - THROTTLE AND ACTUATOR