Project TDI

August 15th, 2011

Text and Photos by Chris Tobin

The latest project vehicle in the Diesel World stable is this ultraclean 2006 VW Jetta TDI.

Buying a Used TDI for Fun and MPGs

Many of us realize that fuel prices will likely never drop back down to levels we’ve enjoyed in the past. The problem is bad enough that some diesel enthusiasts are considering selling their diesel trucks in favor of smaller and more economical daily drivers. So, why can’t you have your diesel cake and eat it too? You can.

The Diesel Alternative

With on-road mileage hovering around 50 mpg right off the showroom floor, VW’s TDI lineup of cars is a great alternative to gas-sipping rice-burners. You can get a two-door Golf, four-door Jetta sedan or even a TDI Jetta wagon, all with a 1.9L turbo diesel powerplant and in either stick or automatic. And with all the new emissions equipment on the new models, the hot ticket is to find an earlier model that is a 2006 or older, since VW pulled them off the market after the 2006 models. They returned in 2010, fitted with more-extensive emissions equipment to meet new government standards.

Under all this plastic is a cool 1.9L turbo diesel engine. In stock trim, the car got nearly 50 mpg, even when loaded with people and luggage.

The TDI turbo diesel is no slouch. It’s a single overhead cam (SOHC), 1.9L turbo diesel, and inline, four-banger. It features an iron block and aluminum cylinder head and displaces 116 cubic inches. From the factory, the little diesel is rated at 100 horsepower at 4,000 (which are pretty good rpms for a diesel) and a whopping 177 lb/ft of torque at a low 1,800 rpm.

It isn’t a quarter-mile screamer with ETs in the 18-second range, but we’ve seen a few folks win the bracket racing-based diesel drags with them … and they had to leave promptly afterward before the angry mob of truck owners showed up.

The interior of this car was absolutely pristine for a car with slightly more than 90,000 miles on the odometer.

Best of all, there’s a growing market of performance parts available for the TDI. Many of the same performance mods you can do on the diesel truck motor, i.e., larger turbos and injectors and electronic upgrades, are all available for the TDI, even though the parts are a lot smaller.

Introducing Project TDI

After watching a TDI take the Street Class win at a diesel drag race with some of the most consistent bracket racing passes we’ve ever seen, we had to have one. As is usually the case with fuel prices, the cost of small cars rises in proportion with the fuel costs, so good used TDIs still carry a good price.

After scouring classified ads and online retailers, we found a 2006 four-door TDI Jetta with a five-speed manual for a decent price. The car was one of those creampuff, unmolested machines that was bone stock with just over 90,000 miles on it. Perfect. And the old adage, “You get what you pay for,” certainly applies to buying a used VW. After a quick and thorough test drive, we were hooked and bought the car.

Mechanical Evaluation

Even though the car seemed to be running great, we had a long distance road trip already scheduled as a shakedown cruise that would take us from the Chattanooga, Tennessee, area to New York City and then upstate New York.

So, being smart after just buying a used vehicle, we headed up to MF Automotive, in Knoxville, Tennessee, where owner Matt Ford and his crew of expert VW and Audi technicians would give our new ride the mechanical once-over.

The first step was a thorough test drive by a mechanic who would hear or feel any malady before we even noticed it. The inspection also included looking at the brakes, wheel bearings and tire pressures and checking for leaks.

The oil looked good, but technician Prince Malmberg changed it, as well as the filter, using high-quality 5W-40 Total synthetic oil that meets VW’s strict requirements for the Pump Deuce TDI engine. While our little Jetta hadn’t rolled over an obscene amount of miles, Ford and Malmberg felt it was best to go ahead and replace the timing belt—before it could give us trouble later on down the road. As is the case with other small, four-banger engines, a timing belt break can spell disaster with low-clearance engines—that is, valves meeting pistons.

Before getting into the belt swap, they decided it was best to verify the condition of the cam and lifters, because some of the TDIs have been known to have wear issues. Our Jetta had relatively low miles and was not showing any of the telltale signs of cam wear, such as rough idle, excessive smoke and noisy valve train, but several of the cam lobes and lifters were showing signs of wear.

Knowing that we would have to be inside the engine soon to change the cam and lifters, and seeing that the current timing belt showed no signs of premature wear, we decided to hold off on changing the timing belt. We would replace it and the cam and lifters all at the same time. We kept to our plan to drive the car on our New York road trip, hoping that the cam and lifters would hold up.

Before finishing the service appointment, Malmberg changed the fuel filter, found that the air filter had very recently been replaced and then replaced the cabin air filter (that had probably never been changed).

During our epic journey, our new Jetta performed flawlessly. The car averaged around 45-46 mpg on the entire trip. The best segment was just over 50 mpg; the worst segment was stop-and-go traffic in New York City. Nevertheless, we still averaged 40 mpgs. It was cool that we could drive more than 500 miles on one tank of fuel, (13.5 gallons)—with some left over.

The ride was comfortable for a small car, and handling was excellent, even with the load of people and luggage on board. Honestly, the car felt more like a 5-day-old car than a 5-year-old car with nearly 90,000 miles on the odometer.

Next month, we’ll dig into the engine and replace the cam and lifters in hopes of eliminating those issues for good. At the same time, we’ll also replace the timing belt and change the oil once again. We also want to strap the Jetta to the dyno to get some baseline performance numbers before we start modifying it. As true diesel enthusiasts, we all know nothing stays stock for long.

If you’re looking for an economical alternative to an 8,000-pound-plus pickup for a daily driver, any one of the TDI series of cars is a great place to start. And from 2006 back, there are plenty of performance parts that are available to boost both performance and mileage. Stay tuned as we show you how much fun you can have with a TDI—without breaking the bank.


MF Automotive

Dept. DW

5611 Washington Pike

Knoxville, TN 37918


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