Having been released in Europe at the end of 2008, and in the United States the following year, it was well-received in all markets. This was good news for the suits in Wolfsburg, because much like the TV makeover shows of its era, the “new” MK6 was essentially just the previous Mark 5 model, in a new dress.
The MK6 is powered by a direct-injected 2.0L turbocharged (CCBZ) engine producing 210hp and 207lb-ft. It is a bit more than the MK5's 197hp, but not by much. Subtle cosmetic changes separate them as well, like sharper headlamps and a wider front grille.
If you own or are thinking of buying a 2008 to 2014 Golf GTI and want to know what to expect in terms of reliability, here are a few things you should look for.
1. Timing Chain Tensioner
Like most modern cars, the intake and exhaust camshafts on the Mark 6 are driven by a chain attached to the crankshaft instead of a belt, like vehicles of old. Volkswagen has moved away from traditional rubber belts because a metal chain has a much longer lifespan.
Unfortunately, this is not the case on the CCBZ engine as it regularly fails. The original design had a large metal ring used to help guide the chain as it rotates. Over time as the chain and tensioner wear, tolerances become looser, and the ring and tension cylinder proved to be inadequate. Some failures occurred under 5,000 miles. When the tensioner fails the valves come into contact with the pistons destroying the engine.
Faced with having to recall tons of one of its best-selling models, Volkswagen acted fast in creating a new design with a thick metal plate instead of the flimsy ring. This seems to have solved the issue but failures still can occur since the chain and tensioner are both wear items
2. Water Pump
If you have ever raised a wrench in anger at a Volkswagen, you know about the cooling system. Volkswagen water pumps are made of plastic and are one of the most common issues you will encounter.
Heat cycling is the main reason why the pump leaks. When plastic gets hot, it expands, and when it cools, it contracts. As a result, the plastic becomes brittle over time, cracking and warping the housing. Changing the water pump is no walk in the park either, as it is located under the intake manifold and sits flat against the block.
You must remove the intake manifold in order to install a new water pump, which requires a triple square, Torx bits, and tough fingernails. Owning a Volkswagen Product will require this part to be replaced at some point, but in my opinion, that is better than owning a BMW and mopping your driveway every two weeks.
3. Carbon Build Up
While you're replacing your water pump, it would be a great idea to look at the back of the valves. Direct injection engines are designed to deliver fuel directly to the combustion chamber. The fuel will burn more efficiently, resulting in increased power production, fuel economy, and reduced emissions. Since no fuel passes over the back of the intake valve, it cannot naturally remove the carbon that builds up.
Over time, the layer of carbon on the valve gets thicker and thicker. It causes a host of issues, such as rough running, ticking sounds, and a lack of power when the cylinder does not seal properly. To remedy the issue, you can go about it in two ways.
First, take it to a reputable Volkswagen shop. There are high-end repair facilities that use walnut blasters, a fine mixture of crushed walnuts or sand that is blown on the carbon part, then vacuumed off.
Here are a few things you need to know if the tree in your yard looks particularly shady that day and you would like to try this procedure yourself.
- You must close the valves on each cylinder as you clean them. If you don't, carbon will fall into the combustion chamber and damage the engine
- Do not turn the crack anti-clockwise! I understand that on old cars you could do this, but on a CCBZ you cannot. The chain can skip and throw off the timing, now you have a serious problem since you may not realize it until the car starts.
- If you use solvent do not use anything chlorinated, and be very gentle as you scrape the carbon off. This can damage the valve.
- Make sure you have a vacuum attachment that fits into the intake port. If your household carpet cleaner or shop vac has a hose you should be fine.
4. High-Pressure Fuel Pump
Continuing with direct fuel injection, the high-pressure fuel pump (HPFP) is another common failure on the Volkswagen MK6 GTI. The CCBZ engine employs two fuel pumps: a low-pressure pump in the tank and a high-pressure pump mounted on the back of the cylinder head.
In order to overcome the enormous pressure inside the combustion chambers, the fuel pressure has to be at least 40bar (480psi) at the fuel rail. Pressure fluctuations can cause the engine to misfire or even not start. HPFP’s are internally lubricated by the fuel flowing through them, so if you run the car low on gas frequently, it can cause the pump to wear out prematurely.
Except for the timing chain issue that has more or less been resolved, as a whole, the MK6 GTI is a great car, it is spacious, comfortable, and awesome to drive. The rest of these problems are common among almost all Volkswagens.
Direct injection is still fairly new compared to port injection, and with new technology comes new problems. If you are thinking of buying an MK6, be sure to get a pre-purchase inspection from reputable Volkswagen specialists, this can save you a lot of headache in the long run.