Used BMW 3 Series Oil Cooler

No — not every 3 Series engine has an oil cooler as standard. Higher-output petrol engines and most diesel engines across the range (including the common M47, M57, N47, N57, B47 and B57 diesel units and performance-oriented petrols) do tend to be fitted with one, but lower-output naturally aspirated petrol engines may not have been equipped with one from the factory. The most reliable way to confirm whether your specific engine has one is to cross-reference against your engine code, which you'll find on your V5C or via a VIN check.

The E46 ran from 1998 to 2006 and the E90 generation ran from 2005 to 2012 — these are entirely different platforms with different engine families, so an oil cooler from an E46 will not cross over to an E90. Fitment is driven by the engine code, not the generation badge, so even if both cars share a similar displacement the cooler design, fittings and brackets are likely to differ. Always quote your engine code to the breaker so they can match the correct unit.

For the oil cooler itself, trim level makes no difference — SE, Sport, M Sport, M Tech and similar trim designations are about interior, cosmetic and suspension specification, not the engine cooling hardware. What matters is the engine code; two 3 Series with identical engine codes will take the same oil cooler regardless of whether one is an SE and the other is an M Sport. Bear in mind that a breaker's oil cooler may come without trim-adjacent brackets or heat shielding if those were fitted differently to your car, so confirm the exact ancillary parts included when you get your quote.

The E90 received its LCI (Life Cycle Impulse) facelift in 2008, and while many engine codes carried across that boundary, ancillary mounting and pipework details can change mid-production even when the core engine code stays the same. The engine code is your best guide and a good starting point, but whether a specific unit from a pre-2008 car fits a post-2008 LCI car is something you should confirm with the breaker against your registration before buying.

The B47 diesel unit was used across the F30/F31 generation (2012–2019) and into the G20 (2019 onwards), and because the engine code is the same, parts often overlap — but output variants (for example B47C20A versus B47D20A) can have differences in the cooling circuit. Treat the engine code suffix as important detail and give the full code to the breaker, not just 'B47', so they can verify the correct match. Never assume fitment across a generation boundary without the breaker confirming against your registration.

No — fuel type directly affects the oil cooler specification, since diesel engines typically run higher thermal and pressure loads and their oil coolers are designed accordingly. A 2.0-litre petrol oil cooler and a 2.0-litre diesel oil cooler are not interchangeable even if the cars look identical from the outside. Always tell the breaker both your engine code and your fuel type to make sure you're quoted the right part.