Disco 4 Second Turbo actuation problem

Hi, I'm a newbie on here and am painstakingly trying to solve the seemingly common 'Restricted Performance' issue when revving my 2010 Disco 4 over 2800rpm. I've cleaned the turbo bypass valve (lower front right), used Turbo Cleaner in the two tanks of fuel, sprayed two cans of Turbo cleaner through the second turbo air intake, but still the problem exists. I notice that the problem does not occur in low ratio; can anyone illuminate me as to why not, and possible 'next steps', please? Thanks!

Has you put it on diagnostics, have you got any codes ? ****ing in the dark without

freelance said:

Has you put it on diagnostics, have you got any codes ? ****ing in the dark without

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Hi, yes, it's the usual P22D3-77 and P22CF-71 which I gather, in theory, relate to Turbo Inlet valve stuck closed and the valve control circuit open, respectively. I have also learnt that the Restricted Performance kicks in at 2800, when the secondary turbo should activate. However, as I said above, this issue does not occur when working in Low Ratio....

I would hazard a guess unless you are towing something really heavy the engine wont see any real load in low range, so no real load = no real power needed= no need for secondary turbo.

Was reading the other day that the secondary turbo is activated every 30 seconds or so even at idle to keep the thing moving.

lynall said:

I would hazard a guess unless you are towing something really heavy the engine wont see any real load in low range, so no real load = no real power needed= no need for secondary turbo.

Was reading the other day that the secondary turbo is activated every 30 seconds or so even at idle to keep the thing moving.

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hi mate

trying to remember , can’t u replace the second actuator , think there’s also a mod for the turbo feed tube

been looking to see if I can find it

lynall said:

I would hazard a guess unless you are towing something really heavy the engine wont see any real load in low range, so no real load = no real power needed= no need for secondary turbo.

Was reading the other day that the secondary turbo is activated every 30 seconds or so even at idle to keep the thing moving.

Click to expand...

Ah, that would explain it, thanks!

gstuart said:

hi mate

trying to remember , can’t u replace the second actuator , think there’s also a mod for the turbo feed tube

been looking to see if I can find it

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Thanks! Yes, there is a mod; I have the pipe, and just need to work out how best to extract the starter motor...! The pipe mod will cure the cause, but i still need to free up the actuator. What's the best way to get to it? I'm thinking i may have to remove the off side wing...

StainmoreLandy said:

Thanks! Yes, there is a mod; I have the pipe, and just need to work out how best to extract the starter motor...! The pipe mod will cure the cause, but i still need to free up the actuator. What's the best way to get to it? I'm thinking i may have to remove the off side wing...

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No many D3 on here and even less D4 so you are either going to be the test pilot, OR pop over to Disco3.co.uk excellent site, search function also works!
Look at the Wiki section at the top of the D3 page loads of useful info/fixes etc in there.

StainmoreLandy said:

Thanks! Yes, there is a mod; I have the pipe, and just need to work out how best to extract the starter motor...! The pipe mod will cure the cause, but i still need to free up the actuator. What's the best way to get to it? I'm thinking i may have to remove the off side wing...

Click to expand...

I think I saw some more info about this , will see if I can find it for u

also heard about cracked manifolds

@StainmoreLandy

here’s the info ref the tube mod

https://www.disco3.co.uk/forum/d4-s...00487-with-photos-132471.html?highlight=Turbo

still looking for the actuator

Turbo control solonoid

I think this is it but will 100% confirm that

https://www.brit-car.co.uk/product....3_0l_diesel___discovery_4___range_rover_sport

Also turbo actuator , part number

LR033284

will find the post for u

Got it, hope it helps

https://www.disco3.co.uk/gallery/albums/userpics/12622/LTB00504v3_-_Compressor_Shut_Off_Valve_(CSOV)_Lower_Level_Repair___TOPIx.pdf