Can anyone tell me the internal diameter of the vacuum pipe from the N75 down to the turbo actuator on a 110 TDi ASV Leon/Toledo?
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TDI Turbo Acutater Pipe Diameter?
- Thread starter Cupra Kid
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From a quick read up I'm getting 3mm ID / 7mm OD. I have 1.9 TDi SE 110 (ASV engine code) myself, only trouble is I can't measure the diameter of the tubing until I get to work, so I can't get you an actual reading until tomorrow morning?
Will that be OK for you mate?
--Lee
Will that be OK for you mate?
--Lee
From a check of VAGcat and then searching for the part number I get
part#N0203535 - vacuum hose - [id]3.5mm [od]7mm.
But the VAGcat diagram is not very clear, and seems to indicate a larger diameter of tube coming off the N75 itself, which makes not sense at all...
The trouble with trying to find the id from a fitted pipe is that you can almost never pull them off without breaking the plastic connectors.
part#N0203535 - vacuum hose - [id]3.5mm [od]7mm.
But the VAGcat diagram is not very clear, and seems to indicate a larger diameter of tube coming off the N75 itself, which makes not sense at all...
The trouble with trying to find the id from a fitted pipe is that you can almost never pull them off without breaking the plastic connectors.
If I'm right the pipe I have disconnected is the same as what is on the turbo actuator, so I was going to check the diameters of that one
I know this isn't anything to do with this thread or topic, but I had my EGR blanked off by plates according to the garage I went to, and I'm assuming that black block connected to the back of the vacuum valve above the electric connector is where the pipe should be connected? Though as I said, this is the pipe I was going to check to see the diameter and see if it's also the same as the one for the actuator on the turbo. As you said though without testing the actual pipe we won't know though your search came up 3.5mm
What do you think Muttley? Worth while check this or not?
--Lee
I know this isn't anything to do with this thread or topic, but I had my EGR blanked off by plates according to the garage I went to, and I'm assuming that black block connected to the back of the vacuum valve above the electric connector is where the pipe should be connected? Though as I said, this is the pipe I was going to check to see the diameter and see if it's also the same as the one for the actuator on the turbo. As you said though without testing the actual pipe we won't know though your search came up 3.5mm
What do you think Muttley? Worth while check this or not?
--Lee
I honestly don't know which tube that is or was. There are two diameters of vacuum tube, as you can see from your photo.
I am going to assume that the one solenoid valve that is still attached to your firewall is the N75 (it's certainly in the right place), but it should have three tubes connected to it: one for vacuum (the top one should be that, and the hoses seem to go to a check valve and a T-piece to a pipe to the vacuum reservoir). one to the turbo actuator (the lower one on the left) and a third, which should be connected to the right-hand side of the solenoid valve, coming from the airbox and a T-piece to the EGR solenoid valve, N18 (which would have been attached to that bracket on the right).
My guess is that the dangling hose is connected to the airbox and used to go to the T-piece. What I can't understand is, what has happened to the connection that should be visible on the right of the N75 solenoid valve?
Let's face it, if that was a vacuum hose and left unplugged, you would have no vacuum . . .
I am going to assume that the one solenoid valve that is still attached to your firewall is the N75 (it's certainly in the right place), but it should have three tubes connected to it: one for vacuum (the top one should be that, and the hoses seem to go to a check valve and a T-piece to a pipe to the vacuum reservoir). one to the turbo actuator (the lower one on the left) and a third, which should be connected to the right-hand side of the solenoid valve, coming from the airbox and a T-piece to the EGR solenoid valve, N18 (which would have been attached to that bracket on the right).
My guess is that the dangling hose is connected to the airbox and used to go to the T-piece. What I can't understand is, what has happened to the connection that should be visible on the right of the N75 solenoid valve?
Let's face it, if that was a vacuum hose and left unplugged, you would have no vacuum . . .
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Yeah, that's very true mate!
I do have 2 solonoid valves attached to the firewall, albeit the one slot which has nothing there to the right, that's been there since I bought the car (empty space that is), as for the connection on the right of the solonoid valve, there is like a "cap", or "stopper / plug" that's connected, I am assuming that was done when I had my EGR plate put on as I can't remember if it was there before or not. I never really checked much concerning the pipes until I started getting curious and wanted to resolve all my boosting issues, what I will do as I'm heading off to work now. Tomorrow I'll start up another thread concerning vacuum pipe work and connections to and from solonoids so it can be seen by anyone who has similar happenings. I only questioned myself concerning this after seeing so many pictures with the connection to the right side of the solonoid valve in question connected up.
I have a pipe that does connect to my air box, I just can't remember off the top of my head where this one is in the loop.
So to carry this on, I'll take some pictures in the morning after work and try to see which exactly this is and give a better picture of my entire vacuum lines, will be much easier that way and my mind will be fresh haha!
Yeah, can't argue with that at all mate, a vacuum is not a vacuum with a leak hole! Thanks again mate and as for Cupra Kid, I'll get back with my diameters in the morning too!
--Lee
I do have 2 solonoid valves attached to the firewall, albeit the one slot which has nothing there to the right, that's been there since I bought the car (empty space that is), as for the connection on the right of the solonoid valve, there is like a "cap", or "stopper / plug" that's connected, I am assuming that was done when I had my EGR plate put on as I can't remember if it was there before or not. I never really checked much concerning the pipes until I started getting curious and wanted to resolve all my boosting issues, what I will do as I'm heading off to work now. Tomorrow I'll start up another thread concerning vacuum pipe work and connections to and from solonoids so it can be seen by anyone who has similar happenings. I only questioned myself concerning this after seeing so many pictures with the connection to the right side of the solonoid valve in question connected up.
I have a pipe that does connect to my air box, I just can't remember off the top of my head where this one is in the loop.
So to carry this on, I'll take some pictures in the morning after work and try to see which exactly this is and give a better picture of my entire vacuum lines, will be much easier that way and my mind will be fresh haha!
Yeah, can't argue with that at all mate, a vacuum is not a vacuum with a leak hole! Thanks again mate and as for Cupra Kid, I'll get back with my diameters in the morning too!
--Lee
Can't get the actual internal diameter for you mate, though the outer diameter for the turbo actuator is definitely 7mm!
Muttley, I've had a good look over my pipes and I'm going to have to do a rough sketch outside later then do a proper drawing that way you can see exactly what's what. I was looking up "1.9 tdi vacuum diagrams" and mine is different to the majority of what I am seeing or I might be looking at it wrongly?
The pipe itself that's not connected up is connected to the solonoid that works the EGR, out the back. That pipe itself comes out the back in to a t-piece, the one section has this pipe on (which I assume should go back in to the N75?) and the other part to this t-piece goes directly in to the air box. From the diagrams I have looked at the pipe that should go directly in to the air box should be the N75 and not the N18 (EGR solonoid)?
I'll definitely have to draw this out and mark it up so it can be seen more clearly, sorry for taking this thread Cupra Kid and sorry I couldn't get you the inner diameter for the specific pipe, all I could get was the outer diameter, that being 7mm.
--Lee
Muttley, I've had a good look over my pipes and I'm going to have to do a rough sketch outside later then do a proper drawing that way you can see exactly what's what. I was looking up "1.9 tdi vacuum diagrams" and mine is different to the majority of what I am seeing or I might be looking at it wrongly?
The pipe itself that's not connected up is connected to the solonoid that works the EGR, out the back. That pipe itself comes out the back in to a t-piece, the one section has this pipe on (which I assume should go back in to the N75?) and the other part to this t-piece goes directly in to the air box. From the diagrams I have looked at the pipe that should go directly in to the air box should be the N75 and not the N18 (EGR solonoid)?
I'll definitely have to draw this out and mark it up so it can be seen more clearly, sorry for taking this thread Cupra Kid and sorry I couldn't get you the inner diameter for the specific pipe, all I could get was the outer diameter, that being 7mm.
--Lee
Thanks for the replys guys, I'll go with 3mm then and should get a nice strong vacuum.
Yes, I'd also noticed that the pipe coming from the actuator to the N75 is two different pipes for some reason joined by a connector. Can't for the life of me think why they didn't use just one long piece?!
Israar - the pipe in you hand goes the airbox just past where the MAF is. Regarding the EGR blanking you can blank off the N18 valve on the bulk head which has pipes going to the EGR (saucer) on the inlet.
N18 controls EGR
N75 controls turbo actuator
Yes, I'd also noticed that the pipe coming from the actuator to the N75 is two different pipes for some reason joined by a connector. Can't for the life of me think why they didn't use just one long piece?!
Israar - the pipe in you hand goes the airbox just past where the MAF is. Regarding the EGR blanking you can blank off the N18 valve on the bulk head which has pipes going to the EGR (saucer) on the inlet.
N18 controls EGR
N75 controls turbo actuator
I drew this out myself when I investigated the vacuum system on my ASV engine.
The top diagram is the vacuum system, lower left is the ECU signals (not specifically vacuum related, I just collected all the signal input/outputs and put them together) and bottom right is the inlet/exhaust gas flow, to show the order of components in the systems and how they relate. Is this what you were looking for
The top diagram is the vacuum system, lower left is the ECU signals (not specifically vacuum related, I just collected all the signal input/outputs and put them together) and bottom right is the inlet/exhaust gas flow, to show the order of components in the systems and how they relate. Is this what you were looking for
Let us know how the piping goes Cupra Kid, I'm after replacing all my pipes soonish so they are in better condition!
Thanks, I understand that the N18 controls the EGR but it also controls the Anti-Shudder Valve too from the looks of it? Either that or I'm reading these solonoids completely wrong haha! The Vac-in on the N18 has connections to the Inlet Manifold/ASV actuator, the No return valve which is connected to the N75 Vac-in. Both of which have connections to the Vacuum Reservoir and the Check Valve (?) which is by the Vacuum Pump?
I've looked at your drawing more than I have anything else concerning this piping haha, I even saved it to read it over and over, I just wasn't getting it right in my head when I looked at my pipe work under the bonnet, though once you see how I have hand drawn out my pipe work with pictures to boot too, you'll most likely laugh and say "Yeah, same as my drawing!" Muttley
I'm going to start the thread now anyway guys, again sorry to take so much of your thread, Cupra Kid!
--Lee
Thanks, I understand that the N18 controls the EGR but it also controls the Anti-Shudder Valve too from the looks of it? Either that or I'm reading these solonoids completely wrong haha! The Vac-in on the N18 has connections to the Inlet Manifold/ASV actuator, the No return valve which is connected to the N75 Vac-in. Both of which have connections to the Vacuum Reservoir and the Check Valve (?) which is by the Vacuum Pump?
I've looked at your drawing more than I have anything else concerning this piping haha, I even saved it to read it over and over, I just wasn't getting it right in my head when I looked at my pipe work under the bonnet, though once you see how I have hand drawn out my pipe work with pictures to boot too, you'll most likely laugh and say "Yeah, same as my drawing!" Muttley
I'm going to start the thread now anyway guys, again sorry to take so much of your thread, Cupra Kid!
--Lee
N239 controls the Anti-Shudder Valve.
The solenoid valves are a simple switch, and the N18 and N75 switch the output pipe between vacuum and atmospheric pressure to produce a variable pressure (between atmospheric and whatever the vacuum pressure is) to open the turbo vanes or the EGR valve a variable amount. The N239 is just a switch as the flap is either open or shut, nothing in between, so it doesn't have an atmospheric pressure connection.
There is no connection to the inlet manifold as diesel engines, having no throttle butterfly, do not produce vacuum in the inlet. There is a vacuum pump driven off the camshaft which does that - mainly because the brakes need vacuum for the servo.
The solenoid valves are a simple switch, and the N18 and N75 switch the output pipe between vacuum and atmospheric pressure to produce a variable pressure (between atmospheric and whatever the vacuum pressure is) to open the turbo vanes or the EGR valve a variable amount. The N239 is just a switch as the flap is either open or shut, nothing in between, so it doesn't have an atmospheric pressure connection.
There is no connection to the inlet manifold as diesel engines, having no throttle butterfly, do not produce vacuum in the inlet. There is a vacuum pump driven off the camshaft which does that - mainly because the brakes need vacuum for the servo.
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Than I'm most likely not understanding these solenoids then and the way they work properly... Looking at the way my pipe work is it looks like it has connection to the atmospheric pressure but with it being connected to vac in I'm guessing it has nothing at all to do with the atmospheric pressure?
What are the three connections for then, vac in, vac out and atmospheric? By you saying it's a switch, I think vac in lets air in from atmospheric and vac out stops the atmospheric coming in or am I way off the ball?
--Lee
What are the three connections for then, vac in, vac out and atmospheric? By you saying it's a switch, I think vac in lets air in from atmospheric and vac out stops the atmospheric coming in or am I way off the ball?
--Lee
OK. Forgive me if some of this is obvious, but I've got to start from the basics as I don't know what you already know.
The N75 and N18 valves each have two inputs and one output. The inputs are atmospheric pressure (from the air cleaner) and vacuum, in reality a lower pressure but not a high vacuum. The output is a variable pressure between atmospheric (14 psi or so) and "vacuum" (3 or 4 psi). The solenoid valve achieves this by switching between vacuum and atmospheric, modulating the time spent attached to each line, to get the required output pressure.
These are static pressures, we're not talking about sucking air continuously out of the actuators: they are sealed of course.
The N239 is just a switch, attaching the actuator to the vacuum line when the ECU wants to close the anti-shudder butterfly.
The N75 and N18 valves each have two inputs and one output. The inputs are atmospheric pressure (from the air cleaner) and vacuum, in reality a lower pressure but not a high vacuum. The output is a variable pressure between atmospheric (14 psi or so) and "vacuum" (3 or 4 psi). The solenoid valve achieves this by switching between vacuum and atmospheric, modulating the time spent attached to each line, to get the required output pressure.
These are static pressures, we're not talking about sucking air continuously out of the actuators: they are sealed of course.
The N239 is just a switch, attaching the actuator to the vacuum line when the ECU wants to close the anti-shudder butterfly.
No need to be forgiven mate, you're helping me out and others so the least anyone can be is appreciative of your help! That of which I am!
I should be the one to say sorry as I should have mentioned that I know nothing concerning how they work, apart from be connected to the said components in the engine bay, so basics is where I should be hehe! Again, sorry on my part there mate!
So N75 and N18 are there to adjust the pressure to what is required of the ECU calling from driving either normally or heavy footed, to do that it switches between the atmospheric and vacuum pressure to give the car the boost it needs?
Yeah, the actuators job from what I'm getting is to be adjusted by the solenoid valves (from the requested variable between atmospheric and vacuum) which then dictates to how much air can go through the Turbo or the EGR, albeit different with the N239 (Anti Shudder Valve) with it being a switch. With that being a switch it either opens up or stays closed. Hopefully I'm getting the hang of this properly now haha, sorry if this is a pain for you mate...
Also, started up my own thread concerning the vacuum pipe work with an exact location on all the pipes including the one that isn't connected to anything but fresh air! That way it keeps me from bogging down Cupra Kids thread Israar's 1.9 TDi Vacuum Pipe Connections.
Thanks again for all your help Muttley
--Lee
I should be the one to say sorry as I should have mentioned that I know nothing concerning how they work, apart from be connected to the said components in the engine bay, so basics is where I should be hehe! Again, sorry on my part there mate!
So N75 and N18 are there to adjust the pressure to what is required of the ECU calling from driving either normally or heavy footed, to do that it switches between the atmospheric and vacuum pressure to give the car the boost it needs?
Yeah, the actuators job from what I'm getting is to be adjusted by the solenoid valves (from the requested variable between atmospheric and vacuum) which then dictates to how much air can go through the Turbo or the EGR, albeit different with the N239 (Anti Shudder Valve) with it being a switch. With that being a switch it either opens up or stays closed. Hopefully I'm getting the hang of this properly now haha, sorry if this is a pain for you mate...
Also, started up my own thread concerning the vacuum pipe work with an exact location on all the pipes including the one that isn't connected to anything but fresh air! That way it keeps me from bogging down Cupra Kids thread Israar's 1.9 TDi Vacuum Pipe Connections.
Thanks again for all your help Muttley
--Lee
You are discovering one of the peculiarities of the engine control system: the ECU sends out electrical signals to the solenoid valves which turn them into pneumatic (air pressure) signals which drive the actuators.
My guess as to why there is this peculiar interface is that it keeps the electrical components well isolated from the hot bits of the engine, the turbo and the EGR.
So, the ECU controls boost pressure and EGR dose via the N75 and N18 valves.
The anti-shudder valve (just a butterfly, like you would find in a carburettor: it really confuses some folks) is spring-loaded in the fully open position and is flicked shut when the engine is turned off, to prevent run-on - after all, as long as the engine is turning over, the injection pump is delivering fuel to the injectors, and the fuel cut-off doesn't act immediately, there is still fuel in the pipes.
Looking more carefully at your underbonnet picture and comparing it to one of my old ASV Toledo, I can see that you still have both the N18 and N75 valves in place.
Earlier you said
EDIT - checking my old engine bay photos I was wrong first time around
I think you're almost right: but of the two solenoid valves on your firewall, the right-hand one in the photo is the N75 and controls the turbo vanes: the left-hand one (buried under pneumatic pipework) is the N18 which is now superfluous. So the loose connection would normally have gone onto the right-hand side of the N75 valve. From your other thread I can see that this valve only has two connections... that is not like it was in my old ASV-engined Toledo. Hmmmm......
I do think that the loose pipe is part of the blue-lined atmospheric pressure pipework in my diagram. So the fact that it is disconnected is not a major problem, as he N18 now has nothing to do and your N75 appears not to have an atmospheric pressure connection......
My guess as to why there is this peculiar interface is that it keeps the electrical components well isolated from the hot bits of the engine, the turbo and the EGR.
So, the ECU controls boost pressure and EGR dose via the N75 and N18 valves.
The anti-shudder valve (just a butterfly, like you would find in a carburettor: it really confuses some folks) is spring-loaded in the fully open position and is flicked shut when the engine is turned off, to prevent run-on - after all, as long as the engine is turning over, the injection pump is delivering fuel to the injectors, and the fuel cut-off doesn't act immediately, there is still fuel in the pipes.
Looking more carefully at your underbonnet picture and comparing it to one of my old ASV Toledo, I can see that you still have both the N18 and N75 valves in place.
Earlier you said
EDIT - checking my old engine bay photos I was wrong first time around
I think you're almost right: but of the two solenoid valves on your firewall, the right-hand one in the photo is the N75 and controls the turbo vanes: the left-hand one (buried under pneumatic pipework) is the N18 which is now superfluous. So the loose connection would normally have gone onto the right-hand side of the N75 valve. From your other thread I can see that this valve only has two connections... that is not like it was in my old ASV-engined Toledo. Hmmmm......
I do think that the loose pipe is part of the blue-lined atmospheric pressure pipework in my diagram. So the fact that it is disconnected is not a major problem, as he N18 now has nothing to do and your N75 appears not to have an atmospheric pressure connection......
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