In 1998, the "technical update" (M52TU) upgrades included adding variable valve timing to the exhaust camshaft.

In 1998, the M52TÜ ("Technical Update") was released, adding variable valve timing to the exhaust camshaft (called "double VANOS").

Other upgrades included a new design throttle body with the ASC (traction control) motor built in and throttle cable override, revised coolant passages with an additional drain back passage and a new cooling system with push fit hoses and a separate expansion tank plus[5] a dual length intake manifold (called "DISA") and steel cylinder liners (in the aluminum block) carried over from the previous M52, these replacing Nikasil in March 1998.

Applications: The "technical update" in 1998 included double VANOS, which improved low rpm torque.

Applications: The "technical update" in 1998 included double VANOS, which improved low rpm torque.

Applications: The aluminum M52 engine received criticism in some markets with high levels of sulfur in the petrol during the late 1990s.

Sulfur has a corrosive effect on Nikasil and led to many early M52 and M60 engines having premature bore-liner wear.

Other upgrades over the M52 include lighter camshafts (with increased lift and duration), valve springs and the exhaust system.