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R56 WALNUT BLASTING

We have invested heavily in the Genuine official CAR Walnut blasting equipment & believe we are the only independent specialist to have this main dealer equipment.

If your reading this the chances are your fully aware of the carbon build up on the intake valve stems but in a brief summary:

Technical Stuff

The newer generation R56 CAR Cooper S are high pressure Direct Injected, traditionally low pressure injectors are fitted within the inlet manifold allowing the fuel & air mixture to flow past the intake valves, the unburnt fuel keeps the intake valves clean as it passes past the opening valves into the engine.

The Direct Injectors are situated inside the combustion chamber. The intake valves open to allow the air into the engine, as the valves are closing small particles stick to the valve stems forming unburnt carbon that eventually builds up on the valve stems. The excessive carbon on the valve stems prevents the valves opening & closing correctly. At 4,000 RPM each valve is opening 2,000 times every minute, if the valves are operating smoothly this has a massive effect on engine efficiency, power & will also cause rough running. In some cases the software for the engine control unit releases somethings not right & stores faults for Supper Knock, this basically means the car is misfiring.

Carbon Build Up Symptoms 

There are several issues that can develop to to carbon build up:

  • EML Light on dash, car in limb home mode intermittently

  • Engine running lumpy

  • Low engine power, engine jerky when accelerating

What we do

Before CAR introduced & approved the carbon blasting equipment the only option was to a full cylinder head strip removing the valves & either removing them completely to clean or replacing them with new this process can cost thousands.

The walnut blasting is done without major engine striping, we remove the intake manifold to gain access to the valve stems. We then rotate the engine ensuring the valves we are cleaning are fully closed to prevent anything entering the cylinder bores.

We then attached a CAR special tool that fits perfectly into the intake port, a vacuum cleaner & the CAR walnut blasting equipment are attached to the adaptor.

We then blast approved CAR crushed walnut shells directly on the valves & intake port, the walnut shells are hard enough to remove the carbon but not hard enough to damage the valves or intake port. The vacuum cleaner then sucks out the both the carbon & walnut shells.

When we are satisfied all the carbon has gone we will continue the process on the other 3 cylinders.

On completion we then reset the vehicles engine software to relearn everything with the valves now clean & operating as they did from new to perform to its optimum values.

All this for £250 Inc VAT

Other Recommended Work to Consider

These engines can also suffer from timing chain tensioner problems, if you notice a heavy mechanical rattle from the engine when started from cold (known as the Death Rattle on the internet, it would be a good time to chain the tensioner. If done at the same time as the walnut blasting we can fit a new genuine CAR tensioner for a additional £60 inc VAT.