TerryM

Thanks - I\'ll let you know how I get on. Cheers.

Thanks. So if I follow that guide I should be seeing 12-14psi boost at the inlet manifold at high revs? If only 7psi then that confirms secondary turbo is dead?

Thanks Marky. Boost gauge should arrive later in the week so will play with that prior to pulling turbo. By test it in parallel do you mean force the car into parallel mode to test? If so, how do I force the car into parallel mode? Cheers.

Thanks again Rosssub. Time to pull it out I guess! From my research, my car should have a VF19 as secondary. Chassis code BG5B5CD. Can anyone please confirm this is correct? Would like to get a replacement before taking the old one out.

Thanks Rosssub. I agree that it\'s looking like a dead turbo. Excuse my lack of knowledge about turbos, but if it could spin freely when I had it off, how is it dead? What has gone faulty in the turbo to stop it from making boost?

Thanks Rosssub. Yep it\'s working fine in diagnostics mode. I haven\'t noticed it making a noise when closing. Should I hear a noticeable clap when it\'s closing in diagnostics mode? I\'m still trying to figure out how the secondary is toast when it could be spun when it was off the car not long ago. As suggested above, the shaft may be broken in half which does make sense to me although I was imagine this would be very rare. What else could be wrong with the turbo? If it can spin then it can still make boost right? Also if for some reason the ECV is not closing properly, wouldn\'t that mean the secondary would always be making boost? So again everything is pointing towards a stuffed turbo?

Thanks Marky. Went for a drive and could not hear any sound change when the secondary should kick in. So I\'m assuming the ECV is not getting a signal to open?

Hi guys, thanks for the responses. I have put the car into diagnostics mode and can confirm the correct operation of IACV and ECV. I took off the intake pipe from secondary to TMIC and can confirm no cracks or splits. Even blocked one end and blew in the other to confirm no leaks. ECV did hold a vacuum when I had the vacuum pump on it. Secondary relief valve is sealing properly. Last time I drove it I don\'t think I could hear it change into twin mode and back. I have bought a boost gauge online so when that arrives I\'ll confirm if any boost is being generated on the secondary. Even though the ECV opened during diagnostics mode, I\'m thinking about hooking up a webcam under the bonnet to watch (or not watch) the ECV open during a road test to totally eliminate it. If the ECV is definitely opening during a road test then the only other thing that makes sense to me is a stuffed turbo. Given the secondary could be spun freely with fingers when the engine was out, how could it be seized? Or can it somehow still spin but no produce boost? Is there any other tests to confirm if turbo is stuffed? Thanks for the help so far - much appreciated!! Slowly getting my head around how these twin turbos operate...

Hi all - long time reader, first time poster. I\'ve got a BG5 GTB and it feels like all boost is lost after 4500rpm. Definitely normal boost down low, just nothing when the secondary should kick in. No error codes being generated. I got a solenoid control box from a wrecker and swapped it over. Didn\'t change a thing so have ruled that out unless it has the exact same fault... I managed to borrow a vacuum pump and have confirmed operation of the vacuum controlled valves so happy they are not seized. Next is to buy a boost gauge and check if any boost at all is being generated after 5000rpm. All hoses appear to be connected and don\'t seem to be cracked or perished. The problem was present before the head gaskets were replaced, but when the engine was out we checked the turbos. Both spun fine and had barely any shaft play so assume they are fine. However the secondary turbo had a lot of carbon on the wheel compared to primary. It also was stiffer to spin than the primary but would still spin freely enough. From what I read the throttle position sensor has a part in the secondary turbo coming online. When I tested the sensor with a multimeter I got infinite resistance (open circuit) no matter what pins the multimeter were connected to and where the throttle position was so possibly the TPS is buggered? Would a buggered TPS be causing this? Is there any other tips or a check guide/step by step elimination process any one has that could assist in confirming what is causing the problem? Thanks in advance for any help! Cheers