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Old 4th September 2008, 20:38   #1
Tony McWilliams
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Default 2.5 V6 feeling sluggish

For the sometime my Rover 75 2.5 V6 Auto has felt sluggish unless you drive it hard. It feels like the auto gearbox is not changing down unless you kick down hard. Even then there is a big delay before the power comes. Once you get going the car drives lovely. No funny noises etc. Its just driving around town the car doesnt feel right and very sluggish.
Could it be a problem with the inlet manifold?
Some background. About 6 months ago there was a load ticking noise from the mainfold and the car started performimg like it is now. I replaced the VIS value which cured the problem. There is no ticking noise from the manifold with the problem I am having now.

Any ideas?

Many thanks

Tony
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Old 4th September 2008, 22:26   #2
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When was the last service? What's the air filter like; worth replacing? What's the fuel consumption like?
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Old 5th September 2008, 06:13   #3
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The inlet manifold is an obvious suspect, the VIS motors are known for behaving badly.
However I would firstly check the accelerator cable for tightness. Adjust so that it has little slack at the pivot point in the engine bay. If there is slack, it affects the downshift of the box a lot. If adjustment is needed, lift the plastic stopper out of its holder and adjust it by turning it on the thread the required way.
And, for good order, check that nothing obstructs the travel of the accelerator pedal, eg. carpet, rubber mat etc.

Good luck
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Old 5th September 2008, 06:44   #4
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There are two VIS motors. Did you replace both? If not, the other might also be faulty but not causing a noise.
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Old 11th September 2008, 08:12   #5
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Hi Jim

It was serviced about 6000 miles ago (4 months). The filters were replaced. Yes the fuel consumption is up by around 10%

Regards

Tony
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Old 11th September 2008, 08:13   #6
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Hi Kaiser

Thanks for the tip I'll get the accelerator cable checked out

Cheers
Tony
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Old 11th September 2008, 08:15   #7
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Hi Lowedb

I only replaced 1 x VIS (top one easy to get too) Do you know if the two VIS are the the same part?

Cheers
Tony
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Old 11th September 2008, 08:43   #8
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Quote:
Originally Posted by Tony McWilliams View Post
Hi Lowedb

I only replaced 1 x VIS (top one easy to get too) Do you know if the two VIS are the the same part?

Cheers
Tony
No. They're different.

You need to get both vis motors checked, as even new ones out of the box can be unserviceable, as I've personally discovered.

FYI, the 'top' one is the Power motor, and the 'side' one is the Balance motor.

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Old 11th September 2008, 08:48   #9
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It's not just the VIS motors to check, its all the butterfly's that they are connected to! They get gummed up.
Somewhere there is a How to.........?
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Old 11th September 2008, 08:53   #10
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Quote:
Originally Posted by Jules View Post
It's not just the VIS motors to check, its all the butterfly's that they are connected to! They get gummed up.
Somewhere there is a How to.........?
If it were the butterfly's themselves, then the OP would be getting the rattle of death!

I suspect it's the Balance motor, as the OP says round town & low revs the car feels sluggish. It's at low revs that the balance part of the manifold works it's magic with the torque.

There's a How To on cleaning the throttle body - is that the one you refer to Jules?
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