BMW’s 4th generation M3 has almost all the best traits of highly desirable enthusiast cars. Even as early examples approach 15 years of age (at the time of writing), their value has remained relatively stable, thanks to their unique offerings. But with that uniqueness comes bespoke parts...

Injector replacement is part of owning an N54 powered BMW. The Autel MX808 makes the calibration process of your new fuel injectors a little easier with no special software necessary.  Calibrating the flow rates for direct injectors is a requirement on some vehicles when installing new injectors....

BMW’s high-performance nature means that every one of their engines is built with strict tolerances. In the more mechanical days, engine builders carefully measured their clearances to get them right and knew the correct tolerances via a book. Nowadays, BMW publishes engine clearances and...

The BMW M52TU, M54, and M56 engines are all related by their aluminum engine blocks. Until then, all prior M-series straight-six engines had used iron cases, making them strong but very heavy. The switch to an aluminum block with iron liners shed weight over the front axle, subsequently improving...

BMW has always done a good job with its oil scavenging system while retaining the wet sump setup on BMW M cars, and the S55 is no different. While the S55 engine shares a lot of its basic engine block architecture with the non-M N55 engine, it uses an entirely different oiling system which does a...

Engineers have been looking for ways to improve the internal combustion engine since its creation. Various reasons have spawned updates and evolutions, but these days, the general driver is efficiency. Greenhouse emissions are bad, and carbon-neutral modes of transportation don’t exist yet, so...

Cam bearing ledge wear is the most common VANOS-related performance issue on high-mileage N52 and N54 engines and the earliest series of N55s. Due to an overlook in design, there's a seal that will eventually wear and cause a myriad of issues. Although it may appear as a simple oil leak and some...

BMW introduced the pencil-style ignition coil to the US market in 2001 with the S54 engine. The one-piece (coil and spark plug connector are integral) design simplified the preceding two-piece, and within a few years, all of BMW’s engines were using the new style. The M54 engine received these...

Last year, FCP Euro Video Editor Stephen Coppola and I discussed power delivery problems with his SpecE46 (an E46 330i built to an agreed standard) and how he was down on power and speed relative to other cars that should be more or less identical. The engine from his race car is original to the...

Compression testing is one of the most common procedures for checking the relative health of an engine. After all, engines are air pumps, and without compression, they tend not to work well. If you ever want to know where you stand in terms of the overall health of your engine, a compression...