The BMW X3 with E46 M3-Engine and Six-Speed Transmission – A Desirable M SUV Option

To address this question, a daring builder undertook the challenge of transplanting the revered S54 inline-six engine from an E46 M3 into a first-gen BMW X3, complete with a six-speed manual gearbox. This unique vehicle is currently listed for sale on M3List at a remarkably lower price of $19,840 – a mere fraction of the cost of a brand-new X3 M.

Renowned for its naturally aspirated engine that revs up to 8,000 rpm, the S54 is a legendary powerplant from BMW. Originally featured in the E46 M3, as well as the Z3 M and Z4 M, this engine delivers a distinctive metallic exhaust note associated with high RPMs. While swaps into E30 and E36 3-Series models are common, seeing it in an X3 platform is a rarity. Here’s a sample of the captivating S54 engine sound.

The seller indicates that the engine exchange was completed approximately 15,000 miles ago, and they have used the vehicle as their daily driver for about a year following the conversion. The original engine had about 140,000 miles on it; however, crucial components such as rod bearings and the VANOS system were serviced during the transplant process.

Besides the M-sourced engine, the X3 has been transformed into a rear-wheel drive setup, but it can be reconfigured to X-drive if the buyer desires all-wheel-drive capability over spirited driving dynamics. Noteworthy performance enhancements include BC Racing coilovers, a custom oil pump and pan, upgraded headers for an improved exhaust note, and a race-oriented exhaust system that according to the seller, allegedly remains emissions-compliant in Georgia. Sounds intriguing, right?

The X3 base, however, possesses 213,000 miles, yet it appears to be in remarkably good condition despite the mileage. Aesthetically, it has been upgraded with an M-Sport body kit, a dark interior from another vehicle, an M3 steering wheel, ASA custom wheels, and a CarPlay-compatible multimedia system. While CarPlay is convenient for navigation, if I possessed this automobile, I highly doubt I would spend much time tuning in to the radio.

This vehicle is truly a surprise package. An observant individual might spot slight negative camber on the back wheels, but apart from that, it resembles a standard grocery hauler. As per the vendor, it is just marginally heavier than an E46 M3 convertible in terms of passenger weight, yet its design is significantly more practical—and inconspicuous. They have even connected the toggle for the S54’s “Sport Mode” throttle mapping to the X3’s SOS switch.

There might be superior ways to invest 20 grand, but it appears I have misplaced recollection of them. Now, if you will pardon me, I shall be viewing S54 exhaust videos on YouTube.

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