The Volkswagen Passat W8 has an infamously unreliable eight-cylinder engine that even seasoned mechanics won’t touch. One Volkswagen expert and YouTuber is tearing down one of these scary engines and revealing its mysteries for everyone to see.
The Volkswagen W8 engine takes a regular boring Passat and turns it into something strange. It makes less power than the company’s V8 engine, but what it lacks in power it makes up for in a beautiful tailpipe soundtrack. The Passat W8 is one of my favorite vehicles in my collection, but I hope I never have to take that engine apart.
Thankfully, Charles tore down the incredible W8 engine for all to see on his Humble Mechanic YouTube channel:
Humble Mechanic explains that the W8 is a 4-liter engine that is basically two 15-degree V4s smashed together in a 72-degree V shape. While it’s a sizable engine, it produces only 270 horsepower and 273 lb-ft torque. Smaller four-cylinder turbo engines make that kind of power today.
The awesome thing about the W8 is that Volkswagen’s W12 and W16 engines are basically just larger versions of the W8. Some W8 owners like to joke that they have half of a Bugatti Veyron engine.
He starts off the teardown with the intake manifold.
This piece is pretty cool. The intake manifold looks like a useless engine cover, but it’s actually functional and pretty important. Having it in the way does make basic maintenance a little harder, but it’s not a big deal to remove it.
The teardown continues with the removal the wiring harness and the fuel rail. That rail does give a little bit of a clue to the engine’s condition as a couple of injectors look pretty worse for wear.
The Humble Mechanic moves forward, removing one of the valve covers and exposing the the cylinder head on one side of the engine. While there, he shows the engine’s similarities to the smaller Volkswagen VR6 engine.
He continues on, making his way to the timing chains by removing all of the accessories from the engine. It’s here that he spots another scary detail about the engine’s condition.
The belt that drives the engine’s balance shaft is obliterated. Much of the black stuff draping the engine in this area is the belt’s teeth basically turned into powder.
Several more parts get removed from the engine to reveal the timing chains. These look like an absolute nightmare, but Humble Mechanic says that the chains are actually similar to a VR6 engine. Where a VR6 has two chains running up the engine, the W8 has an extra chain to cover the extra bank of cylinders.
He moves on, revealing some spark plugs that aren’t really fit for this engine. Despite the initial concerns, the engine is actually in remarkably decent shape. Once he got the cylinder head off, it was also clear that the engine has been sitting for a while. But eventually, he took apart enough to reveal an adorably tiny crankshaft:
A traditional V8 has a long crankshaft, but thanks to the W8's compact design the crankshaft is roughly similar in size to an engine with half the cylinders.
The pistons are pretty worn out, too, but they look neat in motion.
In the end, it seemed like the engine had thousands of bolts and an incredible number of individual pieces. The W8 engine is a marvel of engineering, even if it ended up in an otherwise boring car.
Definitely check out the rest of the video, as the Humble Mechanic did an awesome breakdown of how it works!
Updated 3/3/22 with new details.