No compression on cylinder 1, valves, pistons removed checked and rebuilt.

Multiair system as I read/see it is four individual solenoids controlling the inlet valves via hydraulic oil pressure from the actuator block sitting on top of the inlet valves the pressure is built up from four individual pumps working off the camshaft, their is no direct contact from the cam to the inlet valves.

I have scoped the solenoid valves using amps clamps and found all signals the same ie zero to a peak of 11-12amps dropping to a steady 5amps for a short while (square waveform) then back to zero. Sorry couldn't post capture on this computer.

So from the above and a slight knocking from the top end i can only presume the failure is in the inlet valve actuator block nothing is sold separate (£667.00) any suggestions or experience of this fault ? Customer is seeking financial help from the dealer as it has only done 39000 miles, so may loose the job but very interesting as new technology comes in.

With the customers ok we will take the actuator block off and have a look inside and keep you posted

Many thanks for reading.