Hi, The Mercedes dealer tested the fuel pressure at the inlet rail, and replaced the submersible pump in the tank, and whilst recently a new fuel filter was fitted, it was replaced again.
The erg valve isn't vacuum operated and has been cleaned and tested 3 times.
The turbo isn't vacuum operated, only by actuator and nozzle.
When the car was first dismantled 3/4 years ago, it was sent to a specialist reconditioner who changed the compression chamber - damaged in the accident, fitted new bearings/seals, and dyno balanced it. When the scanner picked up high and low boost pressure it was sent back to the turbo co. who now say the nozzle was set to high, so they adjusted it, tested the actuator again - ok, and we refitted it. The high boost is now rectified, but the low still exists. An intercooler pipe has been replaced and the intercooler rinsed just in case of a blockage - ok.
Also the MAF meter has been replaced just in case, without effect.
I see that the glow plug light has started to appear pre start, where previously unseen, and the car has improved.
The fuel has had a good dose of dipotane without effect, and the injectors are given as good by the star diagnostics.
Until recently and esp. when cold the car would lack power, make a whooshing noise, then 'pink' and emit a cloud of noticeable smoke, before clearing, but this has now improved. The dealer tried the engine with the exhaust disconnected without success and says he believes the cat and dpf are ok.
The main indicators I experience are - significantly worse when cold, and secondly at no point has the second half of the throttle been effective so the car often struggles when under load (on hills), but the recent resumption of a glow plug light has improved the drivability at present.
Having now spent nearly £2K trying to resolve this issue I'm reticent to spend more without a strong indicator. The management light is still on caused by low boost fault code, although it hasn't been cleared this week