MT Auto Parts Blog | Expert Tips for BMW enthusiasts on BMW Parts, Accessories, Engines and More

Photo by Nicolò Bacchini on Unsplash   The advice to take your BMW diesel on a good motorway run has been repeated so often it's almost become folklore. But there's a specific mechanical reason behind it, and understanding it helps you know not just how often to do it, but exactly what kind of driving counts, and what happens to the BMW diesel particulate filter when it doesn't get what it needs. What the Diesel Particulate Filter Actually Does Every modern BMW diesel engine is fitted with a diesel particulate filter, commonly called the DPF, as part of the exhaust system. Its job is to trap the fine soot particles that a diesel engine produces during combustion, preventing them from being released into the atmosphere. The DPF does this effectively, but it has a finite capacity. As soot accumulates, the filter eventually needs to clean itself, a process known as regeneration. DPF regeneration works by raising the temperature in the exhaust system high enough to burn off the...

Image: BMW B48A20E Complete Engine with just 60K miles, for £3,299.00, mtautoparts.com   Look at BMW's model range and something quickly becomes apparent. The 318i, 320i, and 330i all share the same B48 engine code, the same 2.0-litre four-cylinder, the same displacement, the same basic architecture. Yet the 318i produces around 156hp, the 320i around 184hp, and the 330i around 258hp. How does the same engine produce three entirely different power figures? The answer matters practically, especially when buying a used BMW engine as a replacement. It Starts With the Turbocharger The biggest variable in BMW's turbocharged engine family is boost pressure: how hard the turbocharger forces air into the engine. More air means more fuel can be burned per cycle, which means more power. On the B48 family, higher-output variants run higher boost pressures, achieved partly through different turbocharger specifications and partly through different mapping in the engine management software....

Photo by Tim Meyer on Unsplash A wet footwell in a BMW is one of those problems that tends to get worse the longer it is left. Water sitting on the carpet soaks through to the underlay, creates a damp smell that is very difficult to shift, and, most seriously, can reach the footwell module (FRM), the small but critical control unit mounted under the driver's side dashboard. Once water gets to the FRM, what started as a leak becomes an electrical fault. Here is where to start looking. Blocked or Disconnected Sunroof Drain Tubes This is the most common cause of a wet BMW footwell, and it affects cars with a sunroof or panoramic roof. BMW sunroofs are designed with drain channels at each corner that carry water away from the roof seal and out under the car. When these tubes block with leaf debris, algae, or sediment, which happens gradually and without warning, water backs up and overflows internally rather than draining away. It typically ends up in the footwell on whichever corner t...

Image: BMW I3 Series Complete LCI LED Headlight, left passenger side, for sale at MT Auto Parts A light mist that appears overnight, then clears once the headlights have been on for a few minutes is one thing. A persistent, heavy condensation that sits inside the lens and does not shift is quite another. Both look similar from outside the car but have different causes. And only one of them actually requires a BMW headlight replacement . Here is how to tell which you are dealing with and what to do about it. Normal Condensation vs a Genuine Fault BMW headlights are not completely sealed units. They contain a small breather vent, sometimes described as a pressure equalisation tube, that allows air to move in and out as the unit heats up and cools down. This vent is intentional and necessary. Without it, repeated pressure changes would eventually compromise the housing. The trade-off is that the vent allows moist air in, which can produce a light condensation film on the inside of the len...