The MK6 GTI is the 6th generation of the legendary Volkswagen Golf.
Released in Europe at the end of 2008, and the next year in the states, 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, this is a morsel more than the MK5s 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 are wondering what to expect in terms of reliability, here are a few things you should look out 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 the traditional rubber belts because a metal chain has a much longer service life.
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, 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 towards a Volkswagen you know about the cooling system. The water pumps are made of plastic and are one of the most common issues you will find on any Volkswagen.
The pump leaks due to a number of reasons but the main reason being heat cycling. When plastic gets hot it expands, and contracts when it cools. Over time, this cycle causes the plastic to become brittle, cracking and warping the housing. It's not like the replacement is a walk in the park either, the water pump is located under the intake manifold and sits flat against the block.
To install a new water pump you need to remove the intake manifold, this requires numerous special tools like a triple square, Torx bits, and tough fingernails. If you own a Volkswagen Product you will have this part replaced at some point, but in my opinion that is better than owning a BMW and mopping oil off your driveway every other week.
3. Carbon Build Up
While you have the intake manifold off replacing your water pump, it would be a really good idea to look at the back of the valves. Direct injection engines are designed to deliver fuel directly into the combustion chamber. This allows the fuel to burn more efficiently, providing a large boost to power production, fuel economy and lowers emissions. The main drawback to this upgrade, since no fuel is passing over that back of the intake valve, is that it can not naturally remove the carbon that builds up.
Over time, the layer of carbon on the valve gets thicker and thicker. This causes a host of issues like rough running, ticking sounds, and lack of power from the cylinder not sealing properly. To remedy the issue you can go about it two ways.
First, take it to a reputable Volkswagen shop. Some high-end repair facilities have walnut blasters, using a fine mixture of crushed walnuts or sand to literally blow the carbon part then, vacuum it out.
If the tree in your yard is looking particularly shady that day and, you would like to attempt this procedure yourself, here's a few things you need to know.
- 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 can not. The chain can skip and throw off the timing, now you have serious problems because you probably won't know until you start the car.
- If you use solvent do not use anything chlorinated, and be very gentle as you scrape the carbon off you can damage the valve easily.
- Make sure you have a vacuum attachment that will fit 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.
To overcome the immense pressures inside the combustion chambers the fuel pressure has to be at least 40bar (480psi) at the fuel rail. Fluctuations in pressure 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.