VAG has a bad time with chains, and the VR6s use two of them. However, the engine also has a problem with occasionally needing a valve cover, as the breather pressure regulator is contained within it, and you have to take the intake manifold off to change it, and while it might not look that bad to do, it is. The direct injected engines require one of the fuel rails be pulled off first, then the intake manifold.
The vacuum pump buried on the back end of the engine also starts leaking oil, which requires.... pulling that darn manifold off for access.
The catalysts are not the longest lasting... and there are two of them.... $700 each, about four hours worth of work to change those.
There are several items on the back end of the head that like to leak oil beside the above mentioned vacuum pump. Like the cam sensors and phasers.
There are also not one, not two, but THREE water pumps.... the two electric ones are a royal pain to access, and they fail far too often than they should.
Thermostat? Well at least the later VR6s they made those so you do not have to remove the engine to change. Seriously. Not kidding. A 12 hour thermostat.
But the VR6's cooling system still remains a complex mess buried in a very difficult to access spot, down below the intake manifold. You have to remember, the VR6 engine came about as a way to shoehorn a larger engine sideways into a FWD car. Why they decided to use them longways in the T'reg is beyond me. The rest of the longitudinal cars use the conventional 90 degree V6s. You'd think with an engine bay big enough to swallow much larger engines (there are not only V8s, but V10s and even a V12
) that the "little" VR6 would have plenty of room to make it easy to service. And in fact, when you first open the hood, it does appear that way... until you literally have to do ANYTHING to one besides maybe spark plugs. Even changing the oil is a pain, because the cartridge oil filter is underneath in a location that strategically barfs oil all over the steering rack, the control arm, and other bits... and that assumes the filter's drain still works properly (most get rounded out by idiots).
I will say, while it is certainly working for its pay, the VR6 (especially the later DI 3.6L) does at least get the portly 2.5 ton SUV down the road OK. Better than you'd expect. But looking at the tach have to visit the right side so much during "normal" driving will merit the abysmal fuel economy.
But the T'reg no matter what powers it tends to eat tires and brakes with alarming speed. The air suspension seems great, until it leaks. And they ALL do eventually. Again the later ones are marginally better.
They tear up driveshafts a lot. I have some customers here on shaft #3 before 90k miles. Luckily you can get them in the aftermarket now... for only $500 or so (less than the dealer).
Good news is, these things tank in value like crazy. So buying one used may put you ahead if you can stomach it taking chunks of your bank account now and then. My friend and mentor bought a decked out V8 model new for $65k, and sold it ten years and 120k well cared for miles later for less than $5k. That's nuts. And it was in flawless condition. The Q7s and Cayennes are even more of a money fire. We see VR6 Cayennes going through auction for less than $3k
Nobody wants them.
Kind of a shame, really, because the bulk of the vehicle is not too bad. Seats, steering, suspension (assuming it has the regular coil springs), switchgear, transmission, differentials, paint, interior, etc. are generally not too bad. Shrunken sunroof drain tubes can and have caused all sorts of problems, but can be remedied without too much stress.
But at the end of the day, Volkswagen's Stupid Useless Vehicle is probably not any better than a Jeep Grand Cherokee and worse than a Toyota 4Runner and while I am Volkswagen's biggest fan I do not see any desire to own one. The V10 TDI is cool just because, but I can see no really good reason to own one and certainly would not want to depend on one as my only conveyance.
Oh, and for the record, the B6 Passat wagon has more interior volume, and was also available with AWD (even here!).