Granturismo S 2011 F1 Exhaust Valve Closed in SPORT mode

[AKCH01]

Hi all,

New owner of a 2011 Granturismo S MC Shift circa 21k miles

Sport button has been working fine until I got in this morning to find the sport button not opening the exhaust valves.
When vehicle is off they are open. They stay open during startup and close once there is engine vacuum. Pressing sport mode & enabling Mc-shift changes the mode however does not open the valves. I can open them by hand no problem and they move as expected (vacuum on idle keeps them shut, removing line opens them as tested both cold & once at temp).
When the rpm are higher the valves open as normal but won't stay open during idle or sub 3.5/4k.

I have done the golf-tee mod for now however keen to understand what may be happening for this to happen. The various threads I've researched and googled don't seem to point to a common answer other than "buy and fit an electric valve".

Any help would be appreciated
Thanks
Alex

 

[Oneball]

It sounds like the electric switch that turns the vacuum on and off has failed.

I think I’m right in saying that at high rpm they are opened by the force of the exhaust gases and not the vacuum being turned off.

 

[AKCH01]

That was along my lines of thinking seeing as both sides are affected. I've looked for diagrams and parts lists to understand where it is but haven't had any luck, do you know where it is &/or fuse location to start testing for potential fixes

 

[Sam McGoo]

From your description, you seem to pretty much understand the system and the obvious and the vacuum isn't being cut when the button pressed, so your next port of call would be the vacuum solenoid valve.
Quite an awkawark bugger to get your fingers on, but you can.
If I remember rightly on my old 2011MC it was mounted up between the divers rear footwell and the boot floor just off center (or there abouts).
If you look with a torch it's the point were the vac pipes from the rear boxes meet, and turn to one. There is also a little electrical connection.

Part 48 below

https://www.eurospares.co.uk/parts/maserati/granturismo-2011/all-pages/additional-air-system-314019

Could be as simple as a lose connection hopefully and a little clean up. Cheap to replace if not.
Check there is voltage getting to the connector when the button is pressed.

Good luck!

Nice first little job for you both to bond

 

[AKCH01]

Hopefully it is something as trivial as that! Thank you so much for the diagram, I hadn't looked under air system! I'll see if I can get under the car tomorrow and play around, assuming it should be sending standard 12v?

 

[Gazcw]

Hopefully it is something as trivial as that! Thank you so much for the diagram, I hadn't looked under air system! I'll see if I can get under the car tomorrow and play around, assuming it should be sending standard 12v?

I hope you have VERY small hands. It is a proper ****** on your back. Ideally drop the back box and remove some of the heat shield if yours is in the same spot as mine. I was looking at it last night to fit the remote on/off system.

 

[AKCH01]

Ah, well that'll make things interesting then! Maybe compromising and leaving them open all the time might be the option until I can get it on a ramp (sorry neighbours!)
Would the tips resting on the bumper be OK or is this a classic full back end dismantle just for a £30 part? US Forums are suggesting also removing the brace

 

[Gazcw]

Ah, well that'll make things interesting then! Maybe compromising and leaving them open all the time might be the option until I can get it on a ramp (sorry neighbours!)
Would the tips resting on the bumper be OK or is this a classic full back end dismantle just for a £30 part? US Forums are suggesting also removing the brace

Don't think it will give you enough space to work. The pipe needs to come out of the way to allow proper access. Very hard to get your hand in there. Can be done but does not allow a lit of movement.

 

[Zep]

To be honest, I think it is working properly. In sport mode on a MC shift, the valves should open at 3500 rpm. They only stay open all of the time on a Stradale or a late Sport.

 

[AKCH01]

I'll have a play tomorrow and let you all know how I get on! Thank all for the help so far!

It's behaving very differently overnight, I was under the impression that sport mode immediately opened the valves even at idle (which is what was happening). It opened/closed fine at the press of the button and now it isn't responding at all.

 

[conaero]

I would first check the action of the valves. You may have correct vacuum cutting in and out but the valves have a tendency to stick.

With pliers, try and work the valves to see if they are sticky

 

[AKCH01]

Thanks for the suggestion, I gave them a squirt of white lithium wd-40 and they move with no resistance. Would have been very surprised if they both got stuck/failed at the same time! When idling (after initial open start) the vacuum sucks them closed and immediately release when engine powers off but don't even attempt to move when button is pressed.
I'll try the solenoid valve @Sam McGoo suggested and work back from there (if my hand fits )

 

[conaero]

My Strad has the same issue, bough a new solinoid valve. It’s on the rear beam by the bumper.

 

[AKCH01]

Thanks @conaero, they seem readily available but out of interest where did you get your part from & did you do it yourself?

 

[Sam McGoo]

To be honest, I think it is working properly. In sport mode on a MC shift, the valves should open at 3500 rpm. They only stay open all of the time on a Stradale or a late Sport.

Probably the one and only time I would go against your wealth of knowledge....

On a 2011 4.7 MC-shift GranTurismo, the valves definitely open at idle and below 3500 rpm when the sport button is pressed.

So @AKCH01 your car has 1 and R buttons for gears yeah? Not a stick

Also, out of interest, in case your car is an earlier one registered late, is your passenger airbag a small slit on the dash? Or a larger rectangle (ie pre or post variator Mod car) as there were subtle changes, but I don't believe the exhaust valve operation was one of them.

 

[Sam McGoo]

Thanks for the suggestion, I gave them a squirt of white lithium wd-40 and they move with no resistance. Would have been very surprised if they both got stuck/failed at the same time! When idling (after initial open start) the vacuum sucks them closed and immediately release when engine powers off but don't even attempt to move when button is pressed.
I'll try the solenoid valve @Sam McGoo suggested and work back from there (if my hand fits )

It's good your valves move so freely, so keep on top of them!
Also, about them failing together, you'd be suprised what they'll do when the get sticky lol.
My 2013 Sport came with both valves stuck SHUT, even at start up, so was always quiet that must have meant the previous owner never had it in sport mode! and they got stuck while driving.

I only manged to free one off enough to work, the other I forced to be stuck open for now. I will try and free it on the bench one day, but suspect a new valve will be required. Open all the time is fine with me, but I do like things to be working correctly.

 

[Scaf]

To be honest, I think it is working properly. In sport mode on a MC shift, the valves should open at 3500 rpm. They only stay open all of the time on a Stradale or a late Sport.

Not so sure about that and think it’s the other way round.
On my old 2010 MC shift the valves are fully open from idle once Sport button pressed.
On my 2014 Strad, in Sport mode they only open over 3500 rpm but are fully open from idle in Race mode

 

[Zep]

Fiat enough chaps. I haven’t had a GTS, but was working on what I remember from driving one. Memories can be faulty!

 

[Gazcw]

Fiat enough chaps. I haven’t had a GTS, but was working on what I remember from driving one. Memories can be faulty!

Especially when riddled with Disarrono

 

[AKCH01]

Probably the one and only time I would go against your wealth of knowledge....

On a 2011 4.7 MC-shift GranTurismo, the valves definitely open at idle and below 3500 rpm when the sport button is pressed.

So @AKCH01 your car has 1 and R buttons for gears yeah? Not a stick

Also, out of interest, in case your car is an earlier one registered late, is your passenger airbag a small slit on the dash? Or a larger rectangle (ie pre or post variator Mod car) as there were subtle changes, but I don't believe the exhaust valve operation was one of them.

Defo the MC-Shift 1 & R (joked with the Mrs the R meant race, let her drive it and when stopped at the light she was about to press R, I very quickly told her it was reverse )

Airbag is a slit, not sure if that's a newer or older model? Car had variator seals done but not sure what the differences are.

Had a look under but you're right, no way my hand is getting in there, exhaust will have to stay open, sorry neighbours