The Worst BMW Engines Ever: Top 5 You Wish You Didn’t Know About
Let’s get one thing straight from the start: saying “BMW makes bad engines” feels a bit like saying “the Germans make bad beer”. It’s just wrong. BMW, after all, is the company that gave us the straight-six symphony, V8 masterpieces, and V12 engines smoother than a Bavarian beer poured by a bartender who’s been doing it since the 1800s.
But even the best engineers occasionally have too much schnitzel and beer at lunch, make a questionable decision, and produce something that leaves owners swearing in three different languages. And so, while it hurts to admit it, here are the five worst BMW engines ever made—the black sheep of an otherwise glorious family.
1. N47 Diesel – The Timing Chain Disaster
On paper, the N47 diesel was efficient, powerful, and perfect for long motorway runs. In practice? It was a mechanical ticking time bomb. BMW had the brilliant idea of putting the timing chain at the back of the engine, meaning that when (not if) it failed, the repair cost was roughly equivalent to the GDP of a small European country. Owners didn’t hear the beautiful hum of German engineering—they heard the sound of their wallets crying.
2. S85 V10 – The Heartbreaker
Yes, it was a Formula 1-inspired masterpiece. Yes, it made a noise that could make angels weep. But it was also about as reliable as a politician’s promise. The S85, found in the E60 M5, had rod bearing issues that could turn your dream super-saloon into an oversized paperweight. Owning one is like dating a supermodel who insists you buy her diamonds every week just to keep her happy. Wonderful, but financially ruinous.
3. M47 Diesel – Swirl Flap Roulette
BMW thought it was a clever idea to put little swirl flaps in the intake manifold to improve efficiency. What actually happened? These little flaps occasionally decided they’d had enough of life, broke off, and flew straight into the combustion chamber—turning your engine into a scrap-metal smoothie. Owners quickly learned that removing the swirl flaps was the only way to keep their sanity.
4. N63 V8 – The Oil-Guzzling Menace
This twin-turbo V8 was supposed to bring effortless power to BMW’s luxury cars. Instead, it brought endless trips to the mechanic. Oil consumption was biblical, valve stem seals failed like clockwork, and the engine ran so hot it could fry an egg on the bonnet. BMW even had to launch a “customer care package” (which is German for “yes, we know it’s rubbish”).
5. E65 7 Series V12 (N73) – Complexity Gone Mad
A V12 should be the crowning jewel of any luxury brand. Instead, the N73 was an over-engineered headache wrapped in a 7 Series. The electronics were a nightmare, the maintenance costs could bankrupt oligarchs, and it reminded everyone that sometimes, too much technology is… well, too much. You didn’t buy this engine; you adopted it like a needy child who constantly demands money and attention.
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Final Thoughts
BMW is still one of the greatest engine makers in the world. For every disaster on this list, there are a dozen engines that are bulletproof, iconic, and beloved by enthusiasts everywhere. But sometimes, even BMW got it wrong.
So the next time someone tries to tell you “BMW engines are unreliable”, just remind them: no, most of them are brilliant. It’s just that these five were a bit… well… let’s call them “experimental failures.”
And if you own one of them? Don’t worry. You’re not unlucky. You’re just part of BMW history—the painful, wallet-emptying part.