Finally started looking at the engine side. Have the usual seals and hose to replace, to fix the usual coolant and oil leak issues.

I am however interested in the following reading.

Boost pressure actuator between Bank1 and Bank2 are different, one of them stuck? any help in interpreting the graph would be greatly appreciated

I may be chasing a problem that doesn't exist, but would be good to know what they mean. The engine runs ok though. SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

I've been wondering the same thing. The controller output seems to bounce around considerably, as if the boost actuator is sticking or is slow to respond.

That's a sticking actuator, there is a strategy in the programming that tries an 'unstick' - which seems to be working for now, I'd investigate further before it becomes an inconvenient problem.

Thanks for that, question is which one?

I am trying to understand the logic. There is a common path to both bank 1 and 2
Turbo>IC> throttle>plenum to each bank

What am I missing? SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

Whichever one you're measuring, which appears to be bank 1 from the graph labels- from another resource

Quote:

What you are seeing here is the classic "unsticking" cycle of the VNT control output stage from the ECU. The current is applied to maximum load, an assessment is made of the effect of this, then a current-limitation model is used to limit damage to the actuator components, including a reversal of current to unlock the actuator gearbox from a potential "gear-blocking" that occurs in this specific type of actuator unit.

Rose joints on these?

Yep, like this

Click image to enlarge

Thanks. I suspected the VGT but will look into all of them. This would explain the sluggish behaviour (at times)


So the primary turbo has the bank 1 actuator then SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

It very much depends on how the software is written, with Ford based stuff, I would expect bank0 and bank1, however, with aftermarket diagnostics sometimes this is translated to 1 & 2. The only way to be 100% certain is to disconnect one (the easiest one to get to!) and see which values are affected, don't go by DTC alone as they could well have been transferred verbatim.

Phoenix wrote:

Yep, like this

Click image to enlarge

That's just an example, it's possible of course (although less likely) that the control ring is sticking but you won't know that until you check the link rods and rose joints.

Probably need to be clear which part we are talking about before school gearing it could be smaller parts relating to it.

Haven't had a chance to look at it, but how many actuators are in the distribution path? SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

One per turbo plus the vacuum operated deactivation - but that is not relevant to the operation of the VGT's.
You need to be checking that both rose joints (one at each end of the actuator rod) is free to move and that the control ring at the turbo (i.e. the part the actuator moves via the actuator rod) is free to move, minor momentary resistance isn't anything particularly to worry about, it's the repeatable, stiffening of the joints or control ring that cause issues. Don't lubricate with copperslip or similar, something like Nickel grease will be OK - the grease will evaporate quickly but leave the base Nickel in the joint to lubricate and block water ingress - and therefore further corrosion. I've heard of oven cleaner being used to un-stick the control rings, never tried it myself but if the only option is to remove the turbo, I guess it's worth a try eh?