M62 Tu Engine - Technical Training: Overview BMW 7 series E38 facelift

OVERVIEW

As of 9/98 production the US market will equip the M62 TU B44 (4.4 liter) in the following models

1. 540i, 540i sport wagon
2. 740i/iL

The M62 TU provides federal emission compliance for current and future model years. Additionally, the required new features, added systems and design changes also improve

1. Fuel efficiency
2. Noise Reduction
3. Idle quality

The fundamental mechanical design and function of the M62 TU is primarily carry over from the proven M62 engine.

The M62 TU is however a new, state of the art engine. It does contain new and unique parts.

The following engine components are new for M62 TU

1. Cylinder heads (VANOS oil ports, Secondary Air Injection Ports)
2. Intake and exhaust camshafts (changes due to VANOS)
3. Hydraulic Valve Actuators - HVA (modified internal design, improved oil retention after
4. engine shut down to prevent noise on next start up)
5. Head covers, gaskets, mounting hardware (Upgraded components due to VANOS)
6. Timing chain cases (accommodation of VANOS and New Water Cooled Generator)
7. Timing Chain Guide Rail (VANOS integration)
8. Pistons/rings (improved ring land hardening process)
9. Cyclone Separator, vent pipe, drain tube (modified for VANOS integration)
10. Ribbed V belt, belt adjusting lever and pulley assembly

Should engine mechanical repairs be necessary, always verify correct part numbers by checking the start of production indicator in the EPC.

In addition to the basic mechanical changes, the M62 TU engine is equipped with

Scheme 740

1. A new Digital Motor Electronics Control System; ME 7.2 (described in detail further on).
2. Variably positioned intake camshaft VANOS system.
3. "EML" Electronic Throttle Control System identified as EDK.
4. Compact water cooled generator (F-alternator).
5. New exhaust system consisting of exhaust manifolds with integrated forward mounted warm up catalytic converters. Additional downstream main catalytic converters.
6. Thermostat controlled transmission fluid/engine coolant heat exchanger system for automatic transmission equipped vehicles (similar to E46 system).
7. Quick connect couplings for radiator/thermostat hoses and transmission fluid lines.
8. New brake booster vacuum amplifier component and location.
9. Non Return Fuel Rail (Running Loss Compliance) (Scheme 740): Cut-Away View Of M62 TU Engine

Graphing Comparative Power Curves (M62 TU - M62). Scheme 741

The variable intake valve timing system on the M62 TU continues to be identified as VANOS. This acronym comes from the German words; VA riable NO ckenwellen S teuerung, which means Variable Camshaft Control.

The M62 TU VANOS system is a new variant providing stepless VANOS functionality on each intake camshaft. The system is continuously variable within its range of adjustment providing optimized camshaft positioning for all engine operating conditions.

While the engine is running, both intake camshafts are continuously adjusted to their optimum positions. This enhances engine performance and reduces tailpipe emissions.

Both camshafts are adjusted simultaneously within 20° (maximum) of the camshafts rotational axis.

This equates to a maximum span of 40° crankshaft rotation. The camshaft spread angles for both banks are as follows.

Identifying VANOS Operation. Scheme 742

Identifying Camshaft Spread Angle Graph. Scheme 743