Exhaust pump activating but no noise change
Discussion
Hi folks, can anyone give me a rough location of the exhaust pump. I've got a switch fitted which I can hear activating when the car is off and I set it, however with the engine running there's no change in note.
Can anyone give me the location of the pump so I can check to see if the baffles are seized (or a pic would be great). Home alone so can't ask anyone to flick it while I climb under the car.
Thanks
Can anyone give me the location of the pump so I can check to see if the baffles are seized (or a pic would be great). Home alone so can't ask anyone to flick it while I climb under the car.
Thanks
If my memory serves me correctly; It was posted else where that the exhaust valves are open at tick-over and only close between 1,000 and 3,250 revs, or something like that.
Go for a drive, with the valves operating you will hear a distinct change in tone at about 3K as the valves open. With them disabled (always open) there will be a constant build in the noise level as the revs rise and a less significant change in tone at 3K.
Go for a drive, with the valves operating you will hear a distinct change in tone at about 3K as the valves open. With them disabled (always open) there will be a constant build in the noise level as the revs rise and a less significant change in tone at 3K.
I have found some pictures.
Think one is DB9 and the other Vantage (one exhaust bypass valve is missing).
Also a picture of a bypass valve, although not sure if it is an Aston Martin version.
My understanding is the valves are open until about 1500rpm, closed until nearly 4000rpm, then open.
Edited by Jon39 on Thursday 2nd April 23:17
Have a look here http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Thanks for the links folks. They are not seized up so it must be a vacuum thing. That said. this one looks a bit worse for wear 
They are working as I had the engine running and could operate them and hear the exhaust quieten down. I'll get the car up in the air and test the lines
Thanks again for the images and links, I recorded a clip on my goPro that I'll upload so anyone else whom needs to know where they are can have a rough guide.
They are working as I had the engine running and could operate them and hear the exhaust quieten down. I'll get the car up in the air and test the lines
Thanks again for the images and links, I recorded a clip on my goPro that I'll upload so anyone else whom needs to know where they are can have a rough guide.
Wow, that really is in a bit of a state.
I managed to free up my valves yesterday which had been previously seized open. A few weeks ago I managed to force them into the closed (noisy) position and disconnected the vacuum tubes, but having fitted a new remote switch I really wanted to try get them working properly.
So I covered them in as much WD40 as possible and after a bit of effort managed to get them moving freely. And they're now working perfectly.
I managed to free up my valves yesterday which had been previously seized open. A few weeks ago I managed to force them into the closed (noisy) position and disconnected the vacuum tubes, but having fitted a new remote switch I really wanted to try get them working properly.
So I covered them in as much WD40 as possible and after a bit of effort managed to get them moving freely. And they're now working perfectly.
Just out of interest how much pressure did you have to apply to manually move them?
I didn't have anyone near to rev the car but when I pushed the valve up the engine went a quieter (I think) When I'd let go it'd return to the position shown in the picture.
I'm just trying to work out what the hell is the loud and 'silent' positions. From the links shared here, I think mine is stuck is noisy.
I didn't have anyone near to rev the car but when I pushed the valve up the engine went a quieter (I think) When I'd let go it'd return to the position shown in the picture.
I'm just trying to work out what the hell is the loud and 'silent' positions. From the links shared here, I think mine is stuck is noisy.
Edited by ds2000 on Tuesday 7th April 14:54
I think yours is stuck in the quiet position. The picture above yours is noisy (the rod fully extended and the little lever hitting its stop).
I found it very hard to move the rods and only managed to successfully extend them fully once I'd disconnected the vacuum tubes (which aren't too hard to pull off). I extended them by levering them using screwdriver. Took a while but managed it in the end.
Yesterday I soaked them in as much WD40 as possible, then placed a flat ended screw driver underneath the right hand valve's rod and applied pressure. It suddenly freed up and after working it for a while became quite easy to move with my fingers. The left hand side is a little easier to get to so didn't need the screw driver.
I found it very hard to move the rods and only managed to successfully extend them fully once I'd disconnected the vacuum tubes (which aren't too hard to pull off). I extended them by levering them using screwdriver. Took a while but managed it in the end.
Yesterday I soaked them in as much WD40 as possible, then placed a flat ended screw driver underneath the right hand valve's rod and applied pressure. It suddenly freed up and after working it for a while became quite easy to move with my fingers. The left hand side is a little easier to get to so didn't need the screw driver.
That valve looks like it was found in the wreckage of the Titanic. Mine needs a bit more than a little bit of force to move them, so I probably need to work a bit more on freeing them up.
Out of interest, your car is a V12, right? I've just noticed that the set up looks a little different to mine and the other valves in the pictures above. Not that this will make much difference to what you're trying to achieve.
Just to mention, the vacuum pump is quite noisy on my car (which may or may not be normal!) so you can tell quite easily that it's working (or trying to).
Find it quite interesting why yours is so corroded. I'm no expert, but I'm sure that big crack at the bottom of the pressure valve thing isn't helping to move the rod in and out. My car has lived its life outside and this is the state of mine (2006 car)
It's a really crap photo but you can just about see how it looks.
Out of interest, your car is a V12, right? I've just noticed that the set up looks a little different to mine and the other valves in the pictures above. Not that this will make much difference to what you're trying to achieve.
Just to mention, the vacuum pump is quite noisy on my car (which may or may not be normal!) so you can tell quite easily that it's working (or trying to).
Find it quite interesting why yours is so corroded. I'm no expert, but I'm sure that big crack at the bottom of the pressure valve thing isn't helping to move the rod in and out. My car has lived its life outside and this is the state of mine (2006 car)
It's a really crap photo but you can just about see how it looks.
Edited by Cockey on Tuesday 7th April 16:45
Thanks again for the pic. I've never been sure if the post key noises are the fuel pump or the vacuum. I'll hopefully have someone at home next time to fire the car up a little bit while I look and listen.
My car was from Scotland, its done 30k and my guess is its one previous owner used it all year around and the salt has attacked this part. Tbh when the car was on ramps I was expecting to have my heart broken when I saw the underside (previous experience of roadsalt on Jap cars) but it was super clean apart from these valves.
My attention was drawn to the crack as well, I've got a pressure gauge somewhere in the garage (Old RX-7 TT Boost guage) so I'll get it sorted now I've got a little more info that's for sure
My car was from Scotland, its done 30k and my guess is its one previous owner used it all year around and the salt has attacked this part. Tbh when the car was on ramps I was expecting to have my heart broken when I saw the underside (previous experience of roadsalt on Jap cars) but it was super clean apart from these valves.
My attention was drawn to the crack as well, I've got a pressure gauge somewhere in the garage (Old RX-7 TT Boost guage) so I'll get it sorted now I've got a little more info that's for sure
Edited by ds2000 on Wednesday 8th April 13:06
Thread resurrection, but this seems the most complete on the exhaust valve problem....
Just had the DB9 serviced and they noted that the valves are stuck. Not sure if open or closed, but no matter. Aston suggestion was a new exhaust at over £2,000!
What’s the best way to free them up? Sprayed Both sides with WD90 this evening with a view to sorting tomorrow. Will the valve rod move up and down if they’re free or will the pneumatic (vacuum) pistons stop movement? Is it a judicious application of a hammer blow straight up to shock the valves a little or should I try and disconnect the rods from the valve (not sure possible) and then apply pliers to rotate the valve pivot plate?
Always appreciate the help and support on this forum.
Malcolm
(Wing mirrors sorted, rear parcel shelf squeak sorted, this problem is next)
Just had the DB9 serviced and they noted that the valves are stuck. Not sure if open or closed, but no matter. Aston suggestion was a new exhaust at over £2,000!
What’s the best way to free them up? Sprayed Both sides with WD90 this evening with a view to sorting tomorrow. Will the valve rod move up and down if they’re free or will the pneumatic (vacuum) pistons stop movement? Is it a judicious application of a hammer blow straight up to shock the valves a little or should I try and disconnect the rods from the valve (not sure possible) and then apply pliers to rotate the valve pivot plate?
Always appreciate the help and support on this forum.
Malcolm
(Wing mirrors sorted, rear parcel shelf squeak sorted, this problem is next)
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