Guys I have just seen this thread that our customer put up. This fault may have been caused by a number of issues, EGT is one of them and this is what we thought on first seeing the turbo - however to be totally confident of the cause it would need to be properly analysed by an actual turbo specialist such as a company who build them and have substantial real knowledge of failure modes.
EGT’s can be raised as a result of to much boost / running a lean AFR or even excessively retarded timing (as per Turbo Anti Lag systems!!). Taking one example from these listed - Lean running can be due to lots and lots of reasons on the TFSI engine and would need proper investigation on its own to pin point anything (even if this was the reason for the fault).
A brand new turbo has now been fitted to the customers car and the old unit has to be returned as a core unit, As the car is in our workshop to be returned to factory stock and looking at how much stuff has been taken off - the fault (if it were a hardware issue) could easily get taken off during this process, the car is still in the workshop now having parts removed!!
We will certainly be checking the car over substantially before it leaves as this failure was only seen once work had got underway on it.
Something that is possibly related and you can see from the image I have attached below - is that this turbo is also leaking exhaust gases from the centre v-band clamp on the turbo housing itself. We have not seen this happen before on any TFSI turbo in our workshop either. Exhaust soot can be seen over a section of the turbo compressor housing.
We do know the rather unfortunate history of this car, and it did get a bit of a large shock load to the exhaust system not to long ago.
There is the possibility that the two events are actually related – large knock to the exhaust transferring a large axial load onto the turbo housing. If the turbo wheel was still spinning at the point of the large load (which I think it would have been) then turbo wheel damage ‘could’ have resulted, it could have been only one section/blade that took an unusual loading and then failed - that would lead to a foreign object being spun around causing more damage. It is just a wild theory but keeping in mind the shock load on the exhaust that would have been transferred we wouldn’t want to rule it out.
For the record JKM haven’t actually seen the need to use the Forge actuator from the testing that we have done, however we acknowledge that that nature of tuning cars will mean that customers will always like to try new products as they come to marketplace. I have not seen any logs from the car running on this actuator myself so I am sorry that I can’t comment further on how much the boost had been over spiking etc.
Above are some of the possibilities of what ‘may’ or may not have caused this failure. Please also note that JKM did not install/configure this cars Stage 2+ code before anyone asks.
One of our workshop Technicians spotted this the moment the turbo was off. The turbo shaft assembly would have been seriously out of balance and may have failed catastrophically if left!
I hope this helps with some extra input. Hopefully its not to confusing for you, my head hurts anyway!
Once the car is back to stock I will be giving it a good road test to see if anything looks wrong.
Keith
