Hi Guys, yes all the above is very valid. We had a car in last week that had had a GTT220 fitted a few months ago. It was only in for brakes but I felt the car was very down on power. I traced to faulty bypass valve actuator. we fitted a brand new one (gtt tweaked prior to fitting), and the car gained approx 50 horse power.
Customer was very nice and even pm'd me a couple of days ago it read;-
'Thankyou Roland.'
'.......Thankyou Roland for repairing my EB Cooper S last week,the brakes are brilliant,and I cant believe just how much power Id lost with that valve problem.It had just gradually degraded over the last 6 monthsand I just did not realise how much zip the car had lost.Now I'm back finding I have to be judicious with the power...'
We have had many cars with this fault that have even been back & forth to the main dealer who say everything is correct. There computer diagnostics will not register any fault codes when the bypass valve actuator breaks 'the computer says no
'
We can diagnose this fault in approx 5 seconds every time. There are other simple faults that cause big power losses, you dont need RR's nor diagnostics to find most of them.
These cars do benefit from a yearly checkup. TBH even if your car is in with us for other work (eg brakes) we'll often spot anything thats amiss. I did cut the old bypass valve actuator open......diagnosis? the spring inside had broken in half through old age fatigue.
Best Regards Roland GTT
