I finally got around to trying some Liqui Moly Diesel Engine Intake Decarb.



I removed the upper intercooler pipes and started the engine - what a racket. Engine still works with no mass flow.

Next with the help of the wife I sprayed it into the intake in 2-3 second bursts (she kept the revs at 2000rpm). I thought the engine was going to shack itself to bits. But gradually it settled down to a smooth idle (but loud) with each spray.

The outcome is improved throttle response and driveability.

Well worth the effort.

Used to do this with Redex about 50 years ago (not Range Rover ) Pour it into inlet manifold, loads of white smoke from exhaust. Looked impressive. Idle speed used to increase after it so its debatable if it made much difference, but you persuaded yourself you had loads more power
Pal of mine fitted an electric fuel pump & reservoir of Redex connected into the inlet manifold in his Cooper S & used to flick it on when at the lights. The car behind vanished in a dense cloud of white smoke, much to the annoyance of the owner Things you got up to when young. Happy days

My recurring "performance reduced" problem has not appeared since carrying out the procedure.