What's this engine part??
Discussion
To further a thread I started the other week: http://www.pistonheads.com/gassing/topic.asp?h=0&a...
A friend has a car, a 1.6 petrol SEAT Ibiza on a 58 plate. It was bought new and is 100% as it left the factor, no mods at all.
However under certain conditions you can get it to make a dumping sound. If you use hard or near full throttle but shift before 4000rpm you hear an audible hissing/whoosing sound, a little bit like the noise an air clutch makes on a lorry or tractor. But most definitely the sound of compressed gas/air being released.
If you go above 4000rpm it doesn't do this. The only other notable thing we've ID'ed is that the car becomes far more jerky when changing gear above 4000rpm when it doesn't make this noise. We don't know if this is related to it or not.
Anyhow, at last I've got some pics of what we "think" is making the noise.
It seems to have a heavy duty rigid hose connected to it that dissappears out of sight down the back of the engine under the airbox, so I don't know were it goes or what it is connected to.
In front of the small hole on the front of the device there appears to be a small amount of black carbon like deposit as though when something "vents" from the hole it leaves a little bit of trace.
So does anyone know what this thing is, what it does and is it at all to do with the car making this noise?
Thanks.
A friend has a car, a 1.6 petrol SEAT Ibiza on a 58 plate. It was bought new and is 100% as it left the factor, no mods at all.
However under certain conditions you can get it to make a dumping sound. If you use hard or near full throttle but shift before 4000rpm you hear an audible hissing/whoosing sound, a little bit like the noise an air clutch makes on a lorry or tractor. But most definitely the sound of compressed gas/air being released.
If you go above 4000rpm it doesn't do this. The only other notable thing we've ID'ed is that the car becomes far more jerky when changing gear above 4000rpm when it doesn't make this noise. We don't know if this is related to it or not.
Anyhow, at last I've got some pics of what we "think" is making the noise.
It seems to have a heavy duty rigid hose connected to it that dissappears out of sight down the back of the engine under the airbox, so I don't know were it goes or what it is connected to.
In front of the small hole on the front of the device there appears to be a small amount of black carbon like deposit as though when something "vents" from the hole it leaves a little bit of trace.
So does anyone know what this thing is, what it does and is it at all to do with the car making this noise?
Thanks.
doogz said:
As for the air being displaced, could be a lot of things. Valve not closing properly? valve stem oil seal gubbed. Could explain why there is air blowing about in the cylinder head as well as the bad running.
I can't really say with any form of certainty, without having had a good nosy about for myself though, but if it's new, take it back and kick up f
k.
It runs fine, I don't think there is anything wrong with it.I can't really say with any form of certainty, without having had a good nosy about for myself though, but if it's new, take it back and kick up f
k.I just don't know what this device is or what the noise is. I'm curious, not concerned.
doogz said:
Na, looks like an oil breather to me? Can you not follow the hose, see where it goes/if it feeds into the airbox?
Not from above the engine, well not at least without ripping out the entire air box, which I doubt would be a 5 min job. I haven't crawled all the way underneath it either, although I'm not sure you'd see much more.In the 2nd pic you can see another hose going back to the airbox, also that's a rubber one as you'd expect for a return or breather. The one on this thing appears to be a solid rigid hose and from the looks of things doesn't go into the airbox at all.
doogz said:
The Wookie said:
Charcoal Canister?
Modern cars still have these?300, thought it was "jerky"?
Our thinking was along the lines of if it has something to try and "smooth" out the changes when you evidently aren't racing or at full chat.
HellDiver said:
It's not an EGR valve, is it? A leaking EGR?
My housemate's diesel Astra has a leaky EGR, sounds like a steam train on occasion (rather than a tractor), and when it's doing it's Rocket impression there's fumes escaping into the engine bay.
I'm pretty sure it's not the EGR valve as the exhaust manifold is on the other side of the block and this doesn't appear to be connected to it.My housemate's diesel Astra has a leaky EGR, sounds like a steam train on occasion (rather than a tractor), and when it's doing it's Rocket impression there's fumes escaping into the engine bay.
But the idea in principle isn't bad. Most EGR valves don't operates at WOT. And whatever makes this noise only operates at certain rpms.
But it's not a leaking air sound. It's a sound of something compressed being released and only happens with hard acceleration and then press the clutch pedal down before 4000rpm. The noise occurs right when you depress the clutch/lift off the throttle. I need to check but I don't know if it does or doesn't make the noise if you just back off the throttle rather than depress the clutch as well though.
wolf1 said:
HellDiver said:
It's not an EGR valve, is it? A leaking EGR?
My housemate's diesel Astra has a leaky EGR, sounds like a steam train on occasion (rather than a tractor), and when it's doing it's Rocket impression there's fumes escaping into the engine bay.
Yes it's an egr valve.My housemate's diesel Astra has a leaky EGR, sounds like a steam train on occasion (rather than a tractor), and when it's doing it's Rocket impression there's fumes escaping into the engine bay.
The reason I ask is unless it uses internal EGR, this doesn't appear to be attached to the exhaust.
Cheers.
That's a Breather. Take it from me!
As for the noise. Have you tried sticking your head under the bonnet whilst revving it? BTW, air box is easy on that car. Philips head screws all around the edge and the lid comes off. Take out the filter and they'll either be some push fit rubber bungs on the underside. Or some screws in the bottom of the filter housing.
As for the noise. Have you tried sticking your head under the bonnet whilst revving it? BTW, air box is easy on that car. Philips head screws all around the edge and the lid comes off. Take out the filter and they'll either be some push fit rubber bungs on the underside. Or some screws in the bottom of the filter housing.
300bhp/ton said:
wolf1 said:
HellDiver said:
It's not an EGR valve, is it? A leaking EGR?
My housemate's diesel Astra has a leaky EGR, sounds like a steam train on occasion (rather than a tractor), and when it's doing it's Rocket impression there's fumes escaping into the engine bay.
Yes it's an egr valve.My housemate's diesel Astra has a leaky EGR, sounds like a steam train on occasion (rather than a tractor), and when it's doing it's Rocket impression there's fumes escaping into the engine bay.
The reason I ask is unless it uses internal EGR, this doesn't appear to be attached to the exhaust.
Cheers.
They get very hot - so are not made of plastic.
I still think it's a crank case vent/breather (PCV).
petrolveins said:
Not sure this is of much help, but i've got the same engine in my fabia, just had a good look at it just now, and everything is just as your photos show, right down to all the labels on the pipes and hoses and I have never heard any sort of dump-valve-esque noises. 
Obviously need to use the right one abit harder then! 
300bhp/ton said:
The reason I ask is unless it uses internal EGR, this doesn't appear to be attached to the exhaust.
Quite a few engines have an EGR tunnel of sorts through the head - the Vauxhall 2.0DTI has 5 exhaust ports on the manifold, one of which routes through the head to the inlet manifold, then to the EGR. The EGR on the Durascrap in the Mondeo is on the side of the head, again not near the exhaust manifold.
But, it seems it's not an EGR you're looking at anyway, so it's all a bit academic.
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