Your car has a M52TUB25 engine in it. That's probably a little confusing so lets break it down.
- M52 is the engine family
- TU means technical upgrade. In this case the upgrade was from the signal VANOS on the inlet cam used by the M52 family to the dual VANOS on both cams technology. The same as the M54 engines.
- B25 means it is a 2.5L engine.
You have 2.5L engine, but why is it labeled a 2.3L? The M52TUB25 was detuned a little with a focus on fuel efficiency. The horse power of the engine is regarded to be the same as a 2.3L engine.
To add to the confusion, if you look under the bonnet/hood at a M52TU engine and the next generation M54 engine, you'll be hard pressed to spot any difference. The easy way to pick the difference is to look for an accelerator cable on the throttle body. The M52TU has one, whereas the M54 does not. In effect, the M52TU was the Beta version of the M54 engine. They share the majority of parts.
How do you get the 2.5L performance out of the M52TUB25? The usual way is to remove the inlet manifold and fit one off a M54 engine. There is a bit of playing around with a throttle body adapter plate, but other wise it's pug and play. A DME tune help get all of the benefits.
- For the M52TUB20 and M52TUB25 use the M54B25 inlet manifold
- For the M52TUB28 use the M54B30 inlet manifold.
Ah, good info, thanks, NZOOZ3. It’s all come together now
to the Forum from West Cumbria, England. The 2.3 was not for sale in the UK, USA only I believe? The 2.3 is actually a 2.5 though marketed as a 2.3, not sure why. Yup, all Z3s are E36/7www.carfolio.com
