There are some true engineering marvels of the automotive world out there, like the Bugatti Veyron, old Formula 1 racers such as the Lotus 78 and even humble city cars like the Scion IQ can have some pretty incredible engineering inside. Now, a teardown of a diesel engine produced by Volkswagen in the early 2000s has proven why it’s one of the most intricate and complex pieces of engineering out there.
The engine in question isn’t something mundane like the three-cylinder diesel you might find in a car like the Polo. Instead, it’s the enormous V10 diesel that VW made for the Touareg SUV and the Phaeton luxury sedan.
The 4.9-liter, twin-turbo, V10 diesel engine is one we’ve lusted over quite a lot here at Jalopnik, after all the Phaeton is a car that we’ll find any excuse to talk about. Now, YouTube channel HumbleMechanic has dug into the workings of this mighty motor to reveal why it’s one of the most complex road-going engines ever made.
To do this, the crew purchased a VW Touareg that was destined for the scrapheap and ripped out its enormous engine. They then set about taking it to pieces in order to uncover some of the quirks and tech that make this engine sing.
The teardown starts with the removal of all the hoses and housing that surrounds the main block of the engine. In the process, HumbleMechanic uncovers all sorts of issues with the engine, like transmission fluid leaks, engine oil leaks and damage that would have cost more than $10,000 to fix and bring the motor back to life.
So instead, it’s become an online science experiment looking into what HumbleMechanic calls the “least serviceable engine ever made.” The reason for its tough reputation becomes clear once a valve cover is removed and the timing gear is revealed. That’s right, this motor has timing gear instead of a timing belt, as Motor1 explains:
Like most aged German-sourced motors, this one, at first glance, looks like a hunk of metal covered in hoses and oil stains. But look closer, and you’ll see none of the normal accessories normally found at the front of the engine—things like the power steering pump, the alternator, or the A/C compressor—are missing. They’ve been moved alongside the block or in the valley of the V shape. Instead of being powered by a serpentine belt, they’re powered by metal gears at the back of the engine.
The V10 TDI uses gears to drive its timing, rather than a belt or a chain. It also uses gears to drive its accessories. This is some real race car stuff, used in a decidedly pedestrian SUV. Volkswagen was on another level with this in the mid-2000s.
It’s at this point that the reason for the engine’s demise is discovered: a worn cam shaft. The shaft on both sides of the V10 is worn, which could have led to the misfires or loss in power that its former owner reported. The fix for this issue would reportedly cost more than $3,500 adds HumbleMechanic, so instead of stopping to address the problem, he continues to tear it to pieces.
After removing several more components, the alternator is uncovered, which leads the host to say that the motor is “not serviceable in any meaningful capacity, but it’s damn cool.” Other parts like the intake manifolds come off, revealing all kinds of gross buildup through years of use, and the front cover is taken off to reveal all kinds of cooling and oil leaks.
It’s a fascinating dive into the workings of this ridiculous engine, which lasted in production for more than six years. In the end, the enormous motor was fitted to just the VW Phaeton between 2003 and 2007, and the VW Touareg from 2002 until 2006 before it was killed off by the German automaker.
Now, VW doesn’t offer a single diesel engine for buyers here in America and European customers only have a three-liter V6 diesel engine to choose if they’re that way inclined.
