Why do my intake valves need cleaning on my Volkswagon, Audi, Seat or Skoda? (TFSI and FSI engines)
| In the picture to the right you can see the carbon build up on the intake valves from an Audi RS4 4.2 V8 FSI engine with 70,000 miles. This carbon build up is up to 2mm thick in places and is a common problem for modern direct injection engines and stems from the crank case ventilation system, redirecting oil vapours through the inlet manifold to be burnt up. Previous engines with port or inlet injection (such as the 1.8T 20V) did not suffer with this problem as fuel was mixed with the air prior to flowing over the intake valves and therefore, the fuel washed any carbon deposits away. As ever, vehicle manufacturers are trying to increase efficeincy and are choosing direct injection (where fuel is injected directly into the combustion chamber) over port injection for their engines. All of the Volkswagen, Audi, Seat, Skoda FSI or TFSI engines are direct injection and suffer from carbon build up. In the picture below you can also see how direct injection works and the fuel spray from the injector completely misses the intake valve, not allowing the valve to be washed from petrol. |  |
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How are the valves and valve ports cleaned on my VAG vehicle?
| The process of cleaning the ports and valves is fairly straight forward, yet great care needs to be taken not to cause any further damage to the head of the engine or the valves themselves. The valves and ports are cleaned with various chemicals and then media blasted along with a neutralising agent. We require the car for 1 full day to strip down the intake and clean the valves and ports. All gaskets are also replaced as necessary. |
How do I know if my valves need cleaning and what difference will it make?
Carbon build up is a natural occurance on direct injection engines and there is pretty much no way of stopping it. Sophisticated catch cans and alternative oils are said to help prevent the build up but will not stop it completely. Generally speaking an engine with only 20,000 miles on the clock will have a sufficient build up of carbon, so we recommend having your intake valves checked at these intervals. Constant misfires, lack of responsiveness and poor fuel economy can also be related and cured by having this service carried out. If you leave the carbon to build up then these problems can only worsen and possibly cause major damage if a sizable carbon pellet falls into the cylinder.
Once the service is complete your engine will feel more responsive, smoother and more powerful. A cleaner intake port will reduce turbulent air flow and therefore your engine can make more power with less effort. It is ideal to combine carbon cleaning with a More-BHP remap to further increase results.
The increases can be felt on the road as the car pulls a lot harder and is less jerky to drive at very low speeds around town.
One of the most affected engines is the 4.2 FSI V8 found in the Audi RS4 and Audi R8. Reports have circulated that owners have been loosing up to 30BHP alone just from a build up of carbon on the intake valves and ports! For a dedicated performance vehicle this is a serious problem that Audi are failing to address.
Kent Automotive ltd VW and Audi Specialist Valve decoking process in Maidstone Kent!
Prices from £350+vat