Audi RS4 V8 in the workshop for an engine management light on the fault was related to the solenoid used to control the secondary air . The solenoid is located underneath the inlet manifold and requires quite a bit of stripping down . Once the manifold was removed we could visibly see the fault a rodent had chewed through the wiring to the solenoid .
Whilst the manifold was off we were requested to carry out an inlet valve carbon clean this vehicle was badly carbon fouled probably one of the worst we have seen . Careful cleaning and blasting using our Tunap system soon restored the inlet valves back to a clean condition .
Whilst we had the manifold removed we also advise removing and testing the injectors for spray patterns atomisation and delivery’s in this case one injector was poor all the others were ok . Once reassembled the fault was cured and a much better running engine .