Consider for a moment the strange case of John and Angie Voight. John had long been an actor of significant note when he fathered Angelina. After a falling out with her dad, Angie changed her last name, and shot to super-stardom as one Angelina Jolie. John never quite slipped into his daughter's shadow, but there's no doubt that miss Jolie's combination of capability and sex appeal propelled her to greater heights of international fame. The VR6 engine is John Voight; quirky and famous in its own right, but equally so for the offspring that it eventually fathered: the awesome W-16 used in the Bugatti Veyron.
If you want your VR6 Jetta to run the way VW intended it to for the longest possible time, you're going to want to use the "severe" service schedule, regardless of your driving conditions. Regular service intervals are at 7,500 miles, per VW, but owners who really care about their cars will go by the severe-duty schedule and halve that, changing the oil every 3,750 miles. At 7,500 miles, you should check your brake pad thickness and replace as necessary. According to owners, these frequent services, in particular the oil change, are critical to keep narrow-angle VR6 engines from chewing up their bearings and killing the oil pump.
This service -- every second or fourth oil change, depending -- includes the usual oil change and brake inspection, but otherwise consists of inspecting the major wear items and fluids. At this interval, you're going to check the levels and inspect your coolant, transmission fluid level, brake fluid, power steering fluid, and the water level in your battery. Fluids should be clean and clear, and not contain sediments, smell burnt, or be any shade of brown or black. Oils should feel slick when rubbed between your fingers. Inspect the exhaust, fuel system and drivetrain -- including the CV joint grease boots -- for leaks. VW also reccomends replacing the air filter at this interval.
At 30,000 miles, replace the automatic transmission fluid and filter, the engine coolant and the passenger compartment AC system air filter. Check the serpentine belt for cracking or splitting, and drive ribs that are completely rounded off on the top. Inspect the grease seals on the ball joints, tie rods and tie rod ends for leakage. At 60,000 miles, it's time to replace your spark plugs. Volkswagen also says that you should bleed and replace your DOT3 brake fluid every two years, regardless of the mileage on the car. The engine takes 5.8 liters of 5W-30 oil, the automatic gets 6.4 liters of Mercon fluid, and the manual takes 4.2 liters.
The VR6 as a whole is a fairly bulletproof engine -- it did, after all, form the basis for the 1,000-horsepower Veyron's nuclear powerplant. But like all machines, it does have its weak point. VW doesn't list it as a service item, but it's a good idea to clean your mass airflow sensor every 15,000 miles or so. The upper rail guide for the timing chain is a known weak spot, and replacing the timing chain every 100,000 miles or so is good practice. Oil pumps and coil packs are known to go out from time to time; the former failure can usually be avoided with more frequent oil changes, and the latter is a starting point for diagnosis if your VR6 starts acting up.
