In short, walnut blasting is the process of removing carbon build up from the intake ports and valves with the use of compressed air and crushed walnut shells.
Blasting at high speeds the walnut media effectively removes carbon deposits and is a quick and easy way to restore performance and economy to your vehicle
The TFSI engines of the modern era are direct injection, this setup allows for improvements in fuel efficiency and performance as compared to conventional fuel injection. However, the disadvantage of this is that the regular cleaning of the intake valves by the fuel being sprayed on the back of them does not happen any more. The intake valves are only in contact with air and blow-by gases from the crankcase breather system also known as the PCV or EGR, Over time these form carbon deposits in the intake tract as well as on the runner flaps and intake valves themselves, this can cause a number of issues as the engine gets older.
If the valves are heavily caked in carbon they may not close properly anymore, and symptoms such as a lumpy idle, vibrations, poor throttle response and poor performance, In some instances we have came accross carbonised deposits dropping off the valve/runners into the combustion chamber causing engine failure.
Unfortunately this carbonising effect is an inevitable by-product of direct injection, The use of additives in the fuel itself is useless, as the fuel does not come into contact with the intake tract or the valves at all.
Some of the symptoms we have came accross on petrol engines are as follows:
TSI / TFSI / FSI Symptoms:
Loss of Power
Cold Start Misfires
Reduced Economy / MPG