On a whole since i had a engine ECU software update back little while ago (was done as part of NOX sensor replacement procedure) its not been so great. From what I read on FB groups it seems to be “a thing”. The gist is that
More specifically, a ‘ dull plopping noise from the intake manifold – when the air filter is removed’. In our case, all the time – the customer had complained for a little while that the engine was noisy. It sounded a bit odd but there wasn’t anything specific that we could say at that point. Until it got worse and it was at the point that it needed