Just because something is new does not mean it is not, or cannot be, faulty. If this were the case, OEMs would have no need to ever offer any warranty and the SOGA would be completely wasted Parliamentary time.

In my previous life as an Automotive R&D Engineer, I have spent a few years in the warranty recovery department of a large Midlands manufacturer. I used to see pallet loads of returned turbos in the warehouse awaiting testing. As it happens, a significant proportion had no fault (dealer misdiagnosis), but a fair proportion were faulty in some way.

Sounds to me like you've an open and shut case. But the question must also be asked about what is the fault with the new turbo and why? Fitting a new turbo is all very well, but were any peripheral actions required that were not carried out? For example, if the original failed due to oil starvation to the bearings, then the cause of the starvation needs to be remedied or else the new turbo would suffer the same fate.

It seems to me that if this does go to County Court, you'll need more info than just "the turbo was not working".

Thanks for the reply, it is basically what I was told by the specialist, sometimes things go wrong, new or old.

I didn't go in to massive detail above, but the specialist told me that the engine revved fine when the wastegate vavle was disconnected, but when reconnected it didn't go above 1500 rpm, indicating that the variable fins inside the turbo were at fault. I'm not mechanically minded but I think I've got the terminology right, but if not he said that it can only be the turbo that is at fault.

This suggests that the "wastegate" is not operating correctly. Turbos with movable internal fins do not have a "wastegate", the variable fins or vanes are a more efficient means of matching turbo output to power demand. Disconnecting the actuator that moves the vanes could affect the performance but the turbo would not be correctly matched to engine revs except at one engine speed and would either over- or under-boost at others.

On engines that do have just a simple wastegate, the wastegate valve is spring loaded shut and the actuator moves the valve in response to inlet manifold boost pressure acting on a diaphragm against the spring.

I have spoken to the garage this morning and they have told me they have ordered a turbo.

As per my note above, if disconnecting the 'wastegate gadget' allowed it to rev, the turbo itself may be ok; the gadget that adjusts the turbo (the actuator) maybe faulty. Some are operated by boost pressure, some from signals from the ECU.

They are usually bolted onto the turbo itself but may not be easy to source separately and in any case need to be set accurately to give the proper response, so ordering a complete turbo and actuator is the safest (but most costly) fix.