MC Shift, Exhuast stuck on LOUD mode!

[Zep]

Hmmm. Pneumatic actuator is stuck then.

 

[stikey]

Solenoid valve maybe?

may be

 

[Gazcw]

may be

I am assuming when race is activated, that operates the solenoid and stops the vacuum.

 

[stikey]

no permeant vacum in or out of race mode

 

[Sam McGoo]

Sounds like it could be the solenoid then.
If you follow the pipe back from the actuator on the drivers side, it'll go into a small space between the rear floor and the boot floor, the actuator is in there (well it is on mine) you'll see the the vac pipes and an electrical connector going to it. Worth checking that out.

 

[stikey]

Sounds like it could be the solenoid then.
If you follow the pipe back from the actuator on the drivers side, it'll go into a small space between the rear floor and the boot floor, the actuator is in there (well it is on mine) you'll see the the vac pipes and an electrical connector going to it. Worth checking that out.

thanks i will look tomorrow see

 

[conaero]

For what it’s worth and to help you work out where the issue is:

The GT vacuum tank is in the offside front of the front subframe.

Next to it is the primary actuator that does not control the exhaust valves.

Black pipes run from here down the offside floorpan and up over the gearbox under the heat shielding to a second actuator that is on top of the rear bumper beam.

This is the actuator that controls the rear valves.

you can pull the input pipe off this actuator and you should get a puff off air to prove it to this point. You can then check the other side to prove the actuator cuts in and out.

The most common failure of the system is seized exhaust valves. Lube and gentle working will usually be enough to free them but if the are really stiff, working them will ultimately result in the butterfly valve shearing off and you will have to remove the rear box to get it out.

If it is seized solid, remove the rear box(es) and lube and work from the inside.

 

[stikey]

the valves

For what it’s worth and to help you work out where the issue is:

The GT vacuum tank is in the offside front of the front subframe.

Next to it is the primary actuator that does not control the exhaust valves.

Black pipes run from here down the offside floorpan and up over the gearbox under the heat shielding to a second actuator that is on top of the rear bumper beam.

This is the actuator that controls the rear valves.

you can pull the input pipe off this actuator and you should get a puff off air to prove it to this point. You can then check the other side to prove the actuator cuts in and out.

The most common failure of the system is seized exhaust valves. Lube and gentle working will usually be enough to free them but if the are really stiff, working them will ultimately result in the butterfly valve shearing off and you will have to remove the rear box to get it out.

If it is seized solid, remove the rear box(es) and lube and work from the inside.

the butterfly valves are free easy to move iv got the puff of air when i pulled the hose of the rear actuator it may be when the x pipe was fitted something has been damaged
thank for the info very good conaero

 

[conaero]

Would say it’s the rear actuator or hose issue back to the valves

 

[stikey]

Thank you will keep you all posted when i get to the bottom of it

 

[conaero]

Also find which fuse it’s in, check that too then multimeter on the plug and switch modes to see if your getting voltage. If you don’t have one rig up a 12v bulb (indicator bulb out rear lights) and some wire.

 

[stikey]

i have one I'm a sparky buy trade

 

[Gazcw]

Can't beat a bulb and a bit of wire. Remember the old man using one for years even after he had multimeters of various type.

 

[stikey]

got under car today when i looked last time the actuators were in closed position and i had vacuum from the hose at the valve actuators
so i disconnected them from the valves sprayed with wd 40 and wired opend the valves for a few days
Today i got under and the actuators are open and no vacuum when i remove the hose could not see the actuator up behind the bumper -floor pan think i need it on a ramp
so vacuum there then to day none in either mode

 

[CatmanV2]

The valves are always open when there's no vacuum so not quite sure what you wired them for?

Dumb question but you had the engine running?

C

 

[Bobby Dandruff]

Hi, my 09 MC Shift has developed an issue with the exhaust sound recently. It appears as though the valves remain open even when not in sport mode. Don't get me wrong, I love the noise but not great when I'm looking to discretely park up on the drive without waking the neighbours.

There is no audible difference in exhaust note when I engage sport mode - hanving researched the forum it seems that some people have experienced the opposite where it is stuck in quiet mode. I've also been underneath to apply some WD40 on the valve/vacuum mechanism which I was able to move around fairly freely anyway so I'm sure this isn't the issue.

Anyone experienced something similar or know a way to fix this so the valves go back to being closed as the default position? No error messages on dash or any other issues with the car that I am aware of!!

Cheers!
Matt

I had the same issue on my Granturismo S - it was picked up and fixed (at some cost!) when it was serviced.

 

[stikey]

yes i did valves are not responding in race same in mode

 

[ensignia]

Should there be an audible difference in sound when pressing Sport then? I always assumed the difference was only at 3k RPM

 

[CatmanV2]

yes i did valves are not responding in race same in mode

So are they stuck open, or closed?

I'm assuming closed. Which is unusual

C

 

[stikey]

yes closed