Fuse 22 - No difference ??

[Arjxh56]

Hi,
How do I check whether the valves are actually working? I looked underneath the car and cannot see or hear anything?
I had the wife rev the car up and down between idle and 3k, and I sat with my ear next to the exhaust.. I clicked the paralight remote on and off, I heard the actual box click as per instructions, but I couldnt tell any difference to the exhaust note?

I think my car is all standard exhaust etc.. I dont know of any mods to it. Im assuming I should be able to hear the difference?

I am going to try a standard fuse in an hour or so just to see if i get the same result.. Any advice would be welcome.

Thanks

[v8woollie]

Arjxh56 said:

Hi,
How do I check whether the valves are actually working? I looked underneath the car and cannot see or hear anything?
I had the wife rev the car up and down between idle and 3k, and I sat with my ear next to the exhaust.. I clicked the paralight remote on and off, I heard the actual box click as per instructions, but I couldnt tell any difference to the exhaust note?

I think my car is all standard exhaust etc.. I dont know of any mods to it. Im assuming I should be able to hear the difference?

I am going to try a standard fuse in an hour or so just to see if i get the same result.. Any advice would be welcome.

Thanks

The vales open at 4000 RPM so you need to rev higher to actuate the valves. Sequence is open below 1500 RPM, closed between 1500 and 4000 RPM and then open again after 4000 RPM.

[AMDBSNick]

v8woollie said:

The vales open at 4000 RPM so you need to rev higher to actuate the valves. Sequence is open below 1500 RPM, closed between 1500 and 4000 RPM and then open again after 4000 RPM.

I suspect it should be loud period if he has the paralight switch fitted

[v8woollie]

AMDBSNick said:

I suspect it should be loud period if he has the paralight switch fitted

Indeed. I think he is trying to see if the vales are operating as they should as the Paralight unit is clicking as normal but the exhaust noise is not changing.

The only way to see if the exhaust valves are operating normally is to put fuse 22 back in and rev past 4000 RPM to actuate them.

[Arjxh56]

v8woollie said:

Indeed. I think he is trying to see if the vales are operating as they should as the Paralight unit is clicking as normal but the exhaust noise is not changing.

Exactly.

I am going to try the normal fuse in and fuse out at 3pm as i have a break between meetings. I will see if that makes a difference to the exhaust note.

From what i see on you tube, the note should be quite different at low revs with the fuse out, and the same with paralight switch keeping the valves open throughout the rev range?

Thanks

[drofnavi]

You probably need to drive the car up the road and give it a good dose of the loud pedal, you should definately hear a big difference at higher revs. You really won't notice any difference at idle.

[peterr96]

drofnavi said:

You probably need to drive the car up the road and give it a good dose of the loud pedal, you should definately hear a big difference at higher revs. You really won't notice any difference at idle.

eh?
At high revs, it won't matter if fuse is in or not... the valves will be open.

Fuse out... loud all the time
Fuse in..... valves close below 4000(ish) providing the valves have not seized.
I'm pretty sure that the valves relax open at standstill so it's pretty unlikely they will seize closed.
Well that's what I thought

[mikey k]

peterr96 said:

drofnavi said:

You probably need to drive the car up the road and give it a good dose of the loud pedal, you should definately hear a big difference at higher revs. You really won't notice any difference at idle.

eh?
At high revs, it won't matter if fuse is in or not... the valves will be open.

Fuse out... loud all the time
Fuse in..... valves close below 4000(ish) providing the valves have not seized.
I'm pretty sure that the valves relax open at standstill so it's pretty unlikely they will seize closed.
Well that's what I thought

Correct except it is 3k rpm according to the workshop manual

AM Vantage V6 Workshop Manual said:

Variable Flow Silencer Assembly
The rear silencer assembly has a variable flow path controlled by two bypass valves.
The system is intended to enhance top end performance in motor sport applications and will not operate in most normal
driving conditions.
By directing exhaust gasses through a modified path at high vehicle speeds, exhaust back pressure is reduced and top end
performance is enhanced.
As engine speed increase from idle, the bypass valve is open until the engine speed is 1500 rpm.
From 1500 rpm to 3000 rpm, the valve is closed
Above 3000 rpm the bypass valves state is load dependent (fully open at higher loads).

[Arjxh56]

Just tried fuse in and fuse out and no exhaust note change?
But... With the fuse in place, I can hear a noise like an electric motor working near the rear wheel when i rev the car. If i take out the fuse, the electric motor noise stops. So i guess the fuse is doing something?

The electric noise is there when the paralight box is connected, and it doesnt matter whether i press the remote, the electric noise doesnt drop out like when i remove the fuse?

I am confused... All i want is a loud switch!

[v8woollie]

Arjxh56 said:

Just tried fuse in and fuse out and no exhaust note change?
But... With the fuse in place, I can hear a noise like an electric motor working near the rear wheel when i rev the car. If i take out the fuse, the electric motor noise stops. So i guess the fuse is doing something?

The electric noise is there when the paralight box is connected, and it doesnt matter whether i press the remote, the electric noise doesnt drop out like when i remove the fuse?

I am confused... All i want is a loud switch!

If the exhaust note is not changing (and assuming is is loud all the time), then it sounds like the valves may be seized open. The motor noise may be it trying to open valves that are already open. Bit hard to tell without hearing the car but you can tell if the valves are open all the time by sticking fuse 22 back in, go for a run and on a straight stretch accelerate in a gear from say 2000 RPM past 4500 RPM. If you don't hear an audible difference in the exhaust note and volume as you go through 4000 RPM then the valves may be permanently open.

[rev-erend]

Was the fuse out when you first looked at it ?

I believe a post somewhere said that the valve could and does get stuck
if the fuse is removed for long periods of time.

Mentioned here : under fuse 22
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[Arjxh56]

Just had a thought. My car was serviced a few weeks ago at AM dealer and i thought that checking and lubricating the valves was something carried out as standard? Wouldnt they have noticed if the valve was stuck?

[shunt]

Try turning the paralight fuse through 180 degrees. It needs to derive it's power on the correct leg of the fuse. Mine was in the wrong way round when i first fitted it, swapped it through 180 and job was jobbed.

[Arjxh56]

v8woollie said:

If the exhaust note is not changing (and assuming is is loud all the time), then it sounds like the valves may be seized open. The motor noise may be it trying to open valves that are already open. Bit hard to tell without hearing the car but you can tell if the valves are open all the time by sticking fuse 22 back in, go for a run and on a straight stretch accelerate in a gear from say 2000 RPM past 4500 RPM. If you don't hear an audible difference in the exhaust note and volume as you go through 4000 RPM then the valves may be permanently open.

ok.. Im going to go for a run with the fuse in. I will then do the same road with fuse out and see if i can tell a difference between 2000 and 4500 rpm. Back in 15min.

[Arjxh56]

shunt said:

Try turning the paralight fuse through 180 degrees. It needs to derive it's power on the correct leg of the fuse. Mine was in the wrong way round when i first fitted it, swapped it through 180 and job was jobbed.

I will also try this once I have worked out if the valves are actually working.. Thanks

[peterr96]

Arjxh56 said:

Just had a thought. My car was serviced a few weeks ago at AM dealer and i thought that checking and lubricating the valves was something carried out as standard? Wouldnt they have noticed if the valve was stuck?

At a franchised dealer... Almost certainly not.
At Trinity or BR .. almost certainly yes

[Arjxh56]

I have just taken it for a spin, with and without fuse.... I really cant tell the difference. If there is a difference it's very very subtle! (from inside the car that is.. Not sure what it sounds like on the street?)

What i have noticed, becuase i am listening very hard, is a noise when accelerating hard that sounds like air sucking/blowing from under the car, not from the engine bay, but from middle to rear from underneath? Is this normal?

I also noticed that whilst the car was standing and idling (after revving and was playing with the fuse), there was fluid dripping from both exhaust pipes on the joint in the middle of the underneath of the car. is this normal??

[v8woollie]

Arjxh56 said:

I have just taken it for a spin, with and without fuse.... I really cant tell the difference. If there is a difference it's very very subtle! (from inside the car that is.. Not sure what it sounds like on the street?)

What i have noticed, becuase i am listening very hard, is a noise when accelerating hard that sounds like air sucking/blowing from under the car, not from the engine bay, but from middle to rear from underneath? Is this normal?

I also noticed that whilst the car was standing and idling (after revving and was playing with the fuse), there was fluid dripping from both exhaust pipes on the joint in the middle of the underneath of the car. is this normal??

Not sure about the other things (the dripping may be aircon condensation) but the difference between fuse in, fuse out, and fuse in going over 4000 RPM is definitely not subtle!

Sounds like you may have an issue with the valves. They are vacuum operated, so the sucking sound may be the valves actuating but stuck. Basically, if you had fuse 22 out and the valves open you would be hard pushed to hear anything from under the car.

[peterr96]

Arjxh56 said:

What i have noticed, becuase i am listening very hard, is a noise when accelerating hard that sounds like air sucking/blowing from under the car, not from the engine bay, but from middle to rear from underneath? Is this normal?

I also noticed that whilst the car was standing and idling (after revving and was playing with the fuse), there was fluid dripping from both exhaust pipes on the joint in the middle of the underneath of the car. is this normal??

IIRC some people advocated removing the vacuum pipes that close the valves because their were rumours that taking fuse 22 out affected something else as well or gave error codes or some other BS.
It's been confirmed by someone that knows (Mike?) that taking out fuse 22 has no side issues. Wildly guessing that the sucking noise could be as a result of someone disconnecting the vacuum pipes.
Water dripping sounds wrong.
As you're clearly unsure, why not pop it back where you got it serviced and let them tell you what is actually going on rather than conjecture by us lot?

[Arjxh56]

hmmm. Sounds like i need a trip into the service dept. I will call them now!

It would be nice to compare 'noise' with another vantage to see if its me or the car!
Anyone live near J40 M1?