Getting the timing belt changed on a Volkswagen TDI is the most important maintenance job throughout the life of the vehicle. A correctly replaced belt will ensure many years of continued trouble-free performance. An incorrect replacement job, however, may spell the end of the engine completely. This article outlines what you need to know and need to ask your repair shop
The timing belt ensures that the top half of the engine, or cylinder head, is in step with the bottom half of the engine. An failed belt will cause both halves of the engine to collide, which often results in complete engine destruction. An improperly installed belt may cause rough running, hard starting, poor fuel economy, smokiness or premature failure.
The Volkswagen TDI (turbocharged direct injection) diesel engine has incredible longevity and relatively simple routine maintenance. Replacing the timing belt is the most difficult job a TDI must undergo, but thankfully it only needs replacing every sixty, eight or one-hundred-thousand miles, depending on model and year. Get it done right the first time, and every time after that.
Get the Right Parts
Unfortunately the timing belt replacement kit from VW and most national stores is dangerously incomplete. In addition to the timing belt itself there is a tensioning assembly – responsible with keeping the belt tight and preventing it from jumping – as well as up to three rollers that direct the belt as it links the top and bottom of the engine together. Stick with good name brands such as SKF or INA for rollers, Litens for tensioners. FAG is also a very well regarded bearing manufacturer. Gates, Continental and Dayco are the best belt manufaturers.
In addition to the timing belt, tensioner and roller(s) there is hardware (nuts and bolts) that hold the associated components together. These too much be replaced. Stay with VW OEM hardware – “Home Depot” bolts may damage the aluminum components, rust or fail completely.
A good timing belt kit should come with all these things, including a complete bolt set. Don’t cheap out on quality or bolts – you’ll regret it. We recommend choosing a kit from a recognized TDI or VW specialty shop that includes all the components above.
Find the Right Shop
VW TDIs are interference engines – if the top of the engine, the head, gets out of time with the bottom end, very bad, costly damage will result. Ask the shop first and foremost if they have done a TDI belt before. If they have, ask if they know how to set the “injection timing” and if they have the proper tools to lock the camshaft in place. Many shops use paint marks to keep the engine in place – this is not sufficient. The best shops will have TDI specialty tools such as Metalnerd tool kits and VCDS (also known as VAG-COM) – a shop that has invested in these items understands how important they are to completing the job correctly.
A good place to start your search the Trusted TDI Mechanics List, hosted by TDIClub.
It might be very wise advice to spend the extra $50-$70 for a waterpump while replacing the timing belt and rollers since the labor of access later is going to make you wish you replaced it.
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I’m ready to replace my timing belt ( 2000 TDI manual transmission ) but I have a question before I get dirty. When I rotate the camshaft sprocket and install the Cam lock, it locks the cam in place. Does this move the flywheel to top dead center? Does this line the pointer at the top of the transmission bell housing to the stamp mark on the flywheel?
No, the cam-lock can be installed 180 degrees away from TDC. You should only move the engine from the crankshaft or wheels, not from the cam-sprocket. Find TDC on the flywheel and THEN lock the camshaft in place.
Since you have the valve cover off on the MKIV you can look at the valves on cylinder one (closest to the timing belt) when getting ready to insert the cam lock and see that both valves are well away from opening. Cylinder 4 has the cam lobes rocking at just closing/opening the exhaust/intake. This is TDC and you should be able to see the TDC mark on the flywheel through the window on the transmission.
Warning, some aftermarket flywheels do not have a TDC mark so the only way to find exact TDC is with a rod inserted into cylinder 1’s glow plug hole. You put a micrometer on the rod and see when it peaks while rotating the engine. Check the TDC location in both rotation directions and split the difference. THEN MARK YOUR AFTERMARKET FLYWHEEL!
My 2006 2.0 TDI passat had a new short engine and cam belt kit fitted in May 2010.
Just last week the car broke down, the diagnosis from a VW dealership states that the tensioning bolt had stripped its threads causing the cam belt to slip extensively and cause damage to the engine.
What could cause the tensioning bolt to strip its threads and should this be covered under the VW parts warranty
Have a question? I am getting ready to replace 2006 VW Beetle TDI timing belt & water pump. The car has 100,000 miles and is 5spd. What else at this time should be checked. It sounds like the exhaust maybe loose also when I start it, it has a very diesel smell. Any info would be great. Thanks
Pat – the 2006 models have the BEW motor. The BEW motor is notorious for breaking the “Lower EGR Pipe”, which then allows exhaust gases to escape into the engine bay and make the inside of the car smell like exhaust.
IDParts stocks the Lower EGR Pipe (BEW) in addition to the complete Timing Belt Kit you need. For the first timing belt at 100,000 miles I would recommend doing the standard kit, you shouldn’t need anything else.
can anyone help my mums got a 03 golf gt tdi and only had 26k mileage and took it for a inspection and they said it needed a new cam belt is this possible as there were no sighns of this occuring and i know a cam belt should last more than 60k mileage at the least. Just wonderd if it being a GT that it made a difference
They could be recommending that due to the age of the timing belt since it is about 9 years old. I don’t know what the replacement spec is for age, but I would think there is one. Ultimately I would just ask the shop why they are recommending the change.
On a 2003 TDI Jetta auto, how often should i be replacing my timing belt?
I have a 2008 jetta TDI. VW recommend changing belt at 60,000 km along with water pump, and all pulleys.