Limp mode 2

w00519772

I asked this question several days ago: https://forums.moneysavingexpert.com/discussion/5187431

I took the car to the Voltswagon garage today and they tell me that two lights came on behind the scenes:

turbo overboost fault
glow plug cylinder

They have advised that they require another £275 to confirm whether the turbo overboost fault is caused by either: actuator; wiring or turbo. If it is the turbo then it will cost another £1500, whereas the actuator costs £200 and the wiring just £30..

I have spoken to another local garage who seem to think they can confirm whether the turbo is at fault for just £45 (instead of £275) and fix the glow plug cylinder for £45 instead of £276.92. They have also said that they can recondition the turbo for £900 (instead of £1500 for a new turbo).

I am interested to receive some feedback on all of this. I believe I have three options:

1) Buy a new car and trade this one in. I reckon it is worth £4500. Not sure how much this problem will take off the value.
2) Ask the Voltswagon garage to make the repairs. The prices do seem to be very high.
3) Ask the backstreet garage to make the repairs. This will mean that I am left with a reconditioned turbo rather than a new one.

The three options above assume that the turbo is at fault. It could still be the Actuator or wiring though I think it is unlikely.