Well actually this is not a ‘fixed and gone’ .. more of a heads-up but, if I can beg your indulgence Peter, I’ll update as required.
Above vehicle arrived Saturday morning suffering from irregular but frequent 'chunk - chunking' noises & the occasional squeak / squeal from the engine.
Driver reported the vehicle stuttered whilst being driven, when the noise was heard. Along with this, live data showed an approx drop of 200 RPM & an engine load value rise consistent with the timing of the 'chunk - chunking'
First impressions/vibration was: the noise was originating from the turbo but the stethoscope & logic soon disproved this. The turbo oil feed pipe was slackened & within half a turn of loosening, oil gushed from the union bolt, discounting oil pressure issues. ( OK, not scientific but enough of a first look to show oil pressure ok .. especially as the union is right in front of you. ) The Auxiliary belt was then removed to discount rotational component failure i.e. A/C compressor intermittent seizing .. .. No change in noise.
The vehicle drives very well, clutch felt excellent .. no judder, drag, roughness or anything that would suggest DMF .. Apart from the noise and faltering that was very consistent with DMF failure. After consideration, it was decided to remove the cam carrier: Upon removing the carrier, it was apparent the the intake cam had both longitudinal & lateral movement in it, closer inspection revealed just two balls left in the bearing located at the timing gear end of the cam & no ball separator at all left around the bearing.
There is no trace of swarf, nor any sign of the missing balls around the cylinder head .. .. I find it hard to believe ATM that ALL traces of the missing bearing parts have disappeared into the sump without some residual evidence on the cylinder head top surface !! I have received the go-ahead for sump removal & inspection / report so will update this thread.
This vehicle is a '61 plate, 2012 MY with 81500 miles on it. Owner, who is a cab driver, only bought it six months ago with 64K recorded; he states he has had oil changed twice since purchase.
This vehicle has now been fixed with a new cam carrier.
No service parts were available for the cam carrier .. A complete new carrier with cams installed being the only option.
The assembly has been modified with the cams now having no bearings, they now have much larger journals that run direct in the carrier.
The sump was removed and sections of ball separator were found, a good clean up of the cylinder head found bearing balls & separator pieces hidden away in nooks & crannies. The oil pump was also removed & found to be in acceptable condition. The oil & filter was changed after 250 miles, with instructions for another change after 1000 miles have been covered.