Project TDI Part 2: Cam Upgrade and Timing Belt Replacement

December 13th, 2011

Text and Photos by Chris Tobin

Adding Reliability and Performance

Knowing in advance of the propensity for pump deuce TDI engines, such as the 1.9 L mill in our ’06 VW Jetta TDI, to have cam wear issues, we planned to tackle the cam and timing belt replacement right away. But, before we tore into the engine and started modifying, we thought it would be best to strap it down to the Dyno Dynamics chassis dyno at Bean’s Diesel Performance to get baseline measurements.

We were pleasantly surprised that despite some cam wear, our little, red TDI managed to belt out 102.1 horsepower and 174 lb/ft of torque. Interestingly, we found that the air conditioning draws a good deal of power from the little TDI (with a loss of 11 hp and 15 lb/ft of torque), so for that little extra oomph when pulling a grade or lining up at a stoplight, shut off the A/C.

After our new Colt Cams camshaft arrived from Kerma TDI, we took the Jetta up to Knoxville, Tennessee, where the VW/Audi experts at MF Automotive were ready to tackle the cam swap and timing belt replacement.

The team at MF recommends replacing the factory water pump (which is driven by the timing belt) when replacing the timing belt, since the factory water pumps use a failure-prone plastic impeller. The new water pumps that MF Automotive uses and recommends use strong and reliable metal impellers. Additionally, the tensioner and idler should be replaced along with the timing belt.

We used a Continental timing belt. Because it is a critical part, we thought it was better to go with a trusted manufacturer, rather than with a generic auto parts store brand.

When replacing the camshaft in your pump deuce engine, be sure to install new lifters and cam bearings, as well as the cam cap bolts, since the ones VW uses are single-use, torque-to-yield bolts. For much better longevity than the factory cam and lifters, the Colt Cams camshaft uses a black nitride coating on the lobes to make the surface harder and less susceptible to wear issues.

While our BRM engine had nitride-coated lifters on the exhaust valves, the intake valve lifters were uncoated. Our new lifters use the black nitride coating on both intake and exhaust valve lifters. We hope that the better quality billet for the cam from Colt and the black nitride coatings will provide much more longevity than the factory combination.

To further hedge our bet, we will be using Schaeffer’s Supreme 9000 full synthetic 5W-40 engine oil that meets VW’s strict (505.01) requirements; we figure if it’s good enough for 1,000-plus-horsepower Cummins and Duramax engines, it should be good for our little Vee-Dub!

Of course, you will also need a new oil filter and 5 quarts of VW-approved 5W-40 synthetic engine oil, as well as VW-approved coolant to replace what is lost when working on the engine. Your parts list should also include a new accessory drive belt, fuel pump gasket, camshaft seal, new engine mount bolts and a valve cover gasket, in addition to the aforementioned items.

If you plan to do the work yourself, places like Kerma TDI and MF Automotive can put together a complete kit with everything you need for your specific car and engine. If you do this work on your own, you will need to buy or rent a few VW specialty tools, such as the cam and crank position locks and tensioner tool, to make the job safer and easier. Or, you can hand the car over to trained and skilled technicians like the ones at MF and have them do the work for you.

We turned our Jetta over to MF Automotive technician Prince Malmberg to perform the operation on our sick TDI. Working above, on the side and below the engine, he removed everything blocking access to the timing belt covers and then removed the covers and the old belt.

Remember that VW TDI engines will suffer serious damage if the timing belt breaks, so don’t wait until it’s too late. And if you don’t know the service history, as well as when the mileage reaches the recommended interval for your particular engine (usually between 60,000 and 90,000 miles), replace the belt.

Malmberg replaced the camshaft and lifters at the same time as the timing belt. If your TDI does not need the cam change, you can still follow the steps shown when changing the timing belt—just omit the parts involving the cam change.

The complete process took Malmberg about seven hours—as a result of our interruptions for photography. He usually performs the job in about five.

If you plan to tackle the project yourself, it will probably take a full day (and possibly a little more), so plan accordingly. As always, practice safe shop techniques and use common sense, especially when working underneath any car or truck.

Even if you won’t be doing the work yourself, follow along over the next few pages to get an idea about what goes on when the experts are working on a TDI engine.


Bean’s Diesel Performance

Dept. DW

210 Rollin Coal Lane

Woodbury, TN 37190


Colt Cams

Dept. DW

2325 264th Street

Aldergrove, BC V4W 2L5, Canada


Kerma TDI

Dept. DW

3000 Eaglebend Drive #13

Box 2142

Avon, CO 81620

877.KERMA-TDI (877.537.6283)

MF Automotive

Dept. DW

5611 Washington Pike

Knoxville, TN 37918


Royal Purple

Dept. DW

One Royal Purple Lane

Porter, TX 77365


This is in the November issue of Diesel World magazine.

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