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Home > Maintenance & Mods (L322) > How stiff should the COSV mechanism be?

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Ffrr-lover

Member Since: 04 May 2021
Location: Lincolnshire
Posts: 640

2012 Range Rover Vogue SE 4.4 V8 Santorini Black

How stiff should the COSV mechanism be?

Hi All!

I have removed my COSV (or is it CSOV??) a few times over the few years I’ve had my car. Each time I check its operation, spray some more lube on it, and press it in and out a few times. It’s the older version with the nut. (4.4 TDV8 on an MY12 model)

After reading another unrelated post, it was suggested to investigate the COSV for their problem… and I started to think about mine. Specifically about how much strength is needed to move the internal flap.

Now the mechanism moves smoothly, it just needs a lot of strength to make the arm move, and in turn for the flap to then “flip”. I’d describe it as needing to push against a big strong spring, rather than resistance. In fact spraying the lube doesn’t affect the operation at all suggesting its not an issue due to grit ingress or friction.

Is this normal?

I am wondering as surely the vacuum used to operate it doesnt have that much strength\pressure? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

13th May 2023 6:02pm

Ffrr-lover

Member Since: 04 May 2021
Location: Lincolnshire
Posts: 640

This is the arm in question that appears to be against a very strong spring…

Click image to enlarge

Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

13th May 2023 6:44pm

Baltic Blue

Member Since: 13 Aug 2015
Location: North Wales
Posts: 3763

2011 Range Rover Vogue SE TDV8 Baltic Blue

Click image to enlarge

The WM doesn’t say how stiff it should be, but explains in detail how it works.
I guess if yours is opening at 2500 rpm and not tripping into restricted performance then it is OK.

When mine failed the engine immediately tripped into RP at 2500 rpm..
Mike. G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

14th May 2023 7:38am

Ffrr-lover

Member Since: 04 May 2021
Location: Lincolnshire
Posts: 640

Cheers Mike
I have a drop in power at around when the second turbo kicks in which I have it yet managed to resolve.
I’m looking to swap my vacuum hoses as an “it’s at that age” job, but it may help with this too.
My thought is that if it needs more strength to push (or more vacuum pressure) then it may flip later than expected… but within the engine fault tolerance limits.
No RP at any point for me.

I have new doughnut hoses, a cleaned plenum, cleaned MAB sensor, fixed throttle body seals, and no more obvious signs of leaks. Also hence replacing the vacuum hoses. And then hence the query about the COSV movement. Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

14th May 2023 9:12am

JayGee

Member Since: 27 Jul 2021
Location: London
Posts: 3193

2012 Range Rover Vogue 4.4 V8 Orkney Grey

Wasn’t there an engine ecu software update regarding the power dip between the turbo’s? 2012 TDV8 Vogue (L322)

14th May 2023 10:00am

Baltic Blue

Member Since: 13 Aug 2015
Location: North Wales
Posts: 3763

https://www.fullfatrr.com/forum/topic38291.html?highlight=cough
This ??
Mike G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

14th May 2023 10:30am

Ffrr-lover

Member Since: 04 May 2021
Location: Lincolnshire
Posts: 640

JayGee wrote:
Wasn’t there an engine ecu software update regarding the power dip between the turbo’s?

Possibly, yes. I remember it as the 80mph hesitation (as per the link from Baltic Blue) rather than a dip between the two turbos. I have purchased the IIDTool update for my ECU, however if I flash my car with it I loose my remap. If it fixes the issue for me then I am happy to then pay for the remap again… but would rather not do it and find it doesnt fix my issue. If I can get a definite “it will fix it” then I’ll go for it…

For now I am looking at other areas (such as the hoses) as they can also be considered good practice to replace anyway; and if all else fails then I can still try the ECU update.

The car hasn’t always done this so I do not see how the ECU flash would fix it for me. The change is more gradual as if something is wearing out, sticking, or not performing as it should be. Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

14th May 2023 12:18pm

Ffrr-lover

Member Since: 04 May 2021
Location: Lincolnshire
Posts: 640

Baltic Blue wrote:
https://www.fullfatrr.com/forum/topic38291.html?highlight=cough
This ??
Mike

Baltic Blue, you had the update on your car?
Before the update did you only notice it but around 80mph? For me it’s every time the engine passes the crossover point. For example, if i travel at 20mph, change the gear to be around 1,500 rpm, floor it…. The car accelerates as expected, has its lull in power and then picks up again when the 2nd turbo kicks in. Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

14th May 2023 12:23pm

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