Technical data (BMW 3 Series E46)

Cylinder head

Maximum allowable surface warping under the gasket is 0.05 mm

Height of new cylinder head:

• 4-cylinder engine M43TU - 141.00 mm
• 4-cylinder engine N42 - 143.30 mm
• 6-cylinder engine - 140.00 mm

Minimum allowable head height (after processing)

• 4-cylinder engine M43TU - 140.55 mm
• 4-cylinder engine N42 - 143.00 mm
• 6-cylinder engine - 139.70 mm

Valves

Plate diameter:

4-cylinder engine M43TU:

• Inlet - 41.40 mm
• Exhaust - 35.60 mm

4-cylinder engine N42:

• Inlet - 31.50 mm
• Exhaust - 28.40 mm

6-cylinder engine:

Engine M54 2.2 l

• Inlet - 30.00 mm
• Graduation - 27.00 mm

Other engines:

• Inlet - 33.00 mm
• Outlet - 30.50 mm

Maximum clearance of valve stems in guides (when measuring on the valve plate, the end of the stem is flush with the guide) — 0.50 mm

Cylinder block

Cylinder diameter (nominal):

• Engine M54TU - 85.00 mm
• Engine N42 - 84.00 mm
• Engine M52 TU - 84.00 mm

M54 engines:

• Volume 2.2 l - 80.00 mm
• Other models - 84.00 mm

Maximum permissible cylinder ovality is 0.010 mm

Maximum permissible cylinder taper is 0.010 mm

Pistons

Piston diameters:

4-cylinder engine M43TU:

• Nominal size - 84.985 mm
• Repair dimensions - nominal + 0.25 mm and + 0.50 mm

4-cylinder engine N42:

• Nominal size - 83.996 mm
• Repair size - nominal + 0.25 mm

6-cylinder engine M52 TU:

• Nominal size - 83.980 mm
• Repair size - nominal + 0.25 mm

6-cylinder engine M54:

Volume 2.2 l:

• Nominal size - 79.980 mm
• Repair size - nominal + 0.25 mm

Other engines:

• Nominal size - 83.995 mm
• Repair size - nominal + 0.25 mm

Working clearance between piston and cylinder - 0.010-0.047 mm

The maximum allowable clearance between the piston and the cylinder is 0.150 mm

Connecting rods

Maximum difference in connecting rod masses is 4000 g

Crankshaft

Axial clearance - 0.080-0.163 mm

Main journal diameter:

4-cylinder engine M43TU:

• Nominal size - 59,971-59,990 mm
• Repair dimensions - nominal - 0.25 mm and - 0.50 mm

4-cylinder engine N42:

• Nominal size - 64.986-65.000 mm
• Repair dimensions - nominal - 0.25 mm and - 0.50 mm

6-cylinder engines:

• Nominal size - 59.971-59.990 mm
• Repair dimensions - nominal - 0.25 mm and - 0.50 mm

Connecting rod journal diameter:

4-cylinder engine M43TU and 6-cylinder engine with variable valve timing:

• Nominal size - 44.50-45.00 mm
• Repair dimensions - nominal - 0.25 mm and - 0.50 mm

4-cylinder engine N42:

• Nominal size - 49.50-50.00 mm
• Repair dimensions - nominal - 0.25 mm and - 0.50 mm

6-cylinder engines:

• Nominal size - 44.50-45.00 mm
• Repair dimensions - nominal - 0.25 mm and - 0.50 mm

Maximum radial runout in the middle main bearing is 0.15 mm

Operating clearance in main bearings:

• 4-cylinder engines - 0.020-0.046 mm
• 6-cylinder engines - 0.020-0.058 mm

Working clearance in connecting rod bearings:

• 4-cylinder engine M43TU - 0.010-0.052 mm
• 4-cylinder engine N42 - 0.028-0.070 mm
• 6-cylinder engines - 0.020-0.055 mm

Piston rings

Gaps in locks:

4-cylinder engine M43TU:

• Upper compression ring - 0.20-1.0 mm
• Second compression ring - 0.20-1.0 mm
• Oil scraper ring - no information

4-cylinder engine N42:

• Upper compression ring - 0.10-0.30 mm
• Second compression ring - 0.20-0.40 mm
• Oil scraper ring - 0.40-1.40 mm

6-cylinder engine M52TU:

• Upper compression ring - 0.10-0.30 mm
• Second compression ring - 0.20-0.40 mm
• Oil scraper ring - 0.25-0.50 mm

6-cylinder engine M54:



Volume 2.2 l:

• Upper compression ring - 0.10-0.30 mm
• Second compression ring - 0.20-0.40 mm
• Oil scraper ring - 0.25-0.50 mm

Other engines:

• Upper compression ring - 0.20-0.40 mm
• Second compression ring - 0.20-0.40 mm
• Oil scraper ring - 0.20-0.45 mm

Tightening torques for connections

• 4-spindle motors - See. Technical data for chapter 2A
• 6 cylinder engines - See. Technical data for chapter 2B