Turbo and EGR solenoid valves

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pugmax
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Turbo and EGR solenoid valves

Post by pugmax »

Hi, I am new to here.

I owned pug 406 2.0L 110 HDI with 104K Kms. This car has been maintained by the agent when it is owned by the previous owner. when I inspected the solenoid valves in bulkhead I saw some modifications done with regards to the connecting valves. I have posted actual picture of the scenario. Can anybody tell why this is done and what would be the impact? Doesn't it matter if I reconnect all these in the way it should be. Appreciate your replies. Thanks.

Image
GingerMagic
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Re: Turbo and EGR solenoid valves

Post by GingerMagic »

That's not right...... :?

The one with the grey plug is the turbo one, the inlet is the one nearest the bulkhead, and the pipe nearest the engine feeds vacuum to the turbo.
The one with the blue plug us the EGR, again the feed is nearest the bulkhead, the front pipe goes to the EGR valve.

Judging by the picture, the feed to the turbo solenoid goes straight to the turbo, bypassing the solenoid, so the waste gate is permanently open, it should be as you have drawn. Maybe the solenoid was faulty, but this isn't the answer.

The feed for the EGR looks like it's coming from somewhere random too...
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
pugmax
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Re: Turbo and EGR solenoid valves

Post by pugmax »

Hi GingerMagic Thanks for the reply. If the turbo solenoid is faulty what would be the appropriate solution? waste gate you mean the air doser?

The feed in the middle red circle I have drawn is just disconnected from the feed in the top red circle and the feed is open. it is not connected to anywhere.
Please suggest me a good solution. my fuel efficiency is not in a satisfactory level too. car is clocked only 104k Kms.
GingerMagic
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Re: Turbo and EGR solenoid valves

Post by GingerMagic »

Sorry, only just noticed you replied... :oops:

The turbo solenoid can be swapped with one from a scrap car, or you can swap the blue plug one over with the turbo one, just for a diagnosis to see if it works.

Firstly, you need to reconnect the turbo solenoid with the correct pipes, so you need to pull the big circled pipe apart, the bit with the white stripe should go onto the thin part of the solenoid, the other part into the bigger connector on the solenoid.

The two smaller circled parts need to be put back together, so the pipe that is hanging down should be pushed into the larger pipe in the top circle.

Once its plumbed in correctly you can see if it works.

If you have any open pipes, then the vacuum that is need to control the turbo is lost into the atmosphere...
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
pugmax
1.8 8v
Posts: 23
Joined: Fri Oct 14, 2016 8:02 am

Re: Turbo and EGR solenoid valves

Post by pugmax »

GingerMagic wrote:Sorry, only just noticed you replied... :oops:

The turbo solenoid can be swapped with one from a scrap car, or you can swap the blue plug one over with the turbo one, just for a diagnosis to see if it works.

Firstly, you need to reconnect the turbo solenoid with the correct pipes, so you need to pull the big circled pipe apart, the bit with the white stripe should go onto the thin part of the solenoid, the other part into the bigger connector on the solenoid.

The two smaller circled parts need to be put back together, so the pipe that is hanging down should be pushed into the larger pipe in the top circle.

Once its plumbed in correctly you can see if it works.

If you have any open pipes, then the vacuum that is need to control the turbo is lost into the atmosphere...
Thanks for the reply friend. I connected the pipes in correct way as you advised. Seems no problem with it. I can hear a turbo whine in 1800 rpm. I driven the car for more than 1000Km. not noticed any problem. Is it ok to keep these pipes in this way. Does solenoid valve trigger an error code when it is not functioning properly?
pugmax
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Re: Turbo and EGR solenoid valves

Post by pugmax »

What would be the bad impact if waste gate is permanently opened?
frog
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Re: Turbo and EGR solenoid valves

Post by frog »

What would be the bad impact if waste gate is permanently opened?
Turbo not spooling up enough, bad driving performance.

Probably there will be a diagnostic trouble code in the motor management.
Current "fleet":
2003 406 Estate 2.0HDi 110 - 7 seater - just hit 690.000 kms :cheesy:
2001 Citroen Saxo 1.6i 8v 100

Previously owned:
2000 406 Sedan 2.0 HDi 90
2000 406 Coupé 2.0i 16v 138 - Riviera Blue

PP2000 user, can help with faults / diagnostics in the Netherlands.
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fattail95
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Re: Turbo and EGR solenoid valves

Post by fattail95 »

Your current EV setup is very...bodged, to say the least. At the moment the wastegate on your turbo is connected directly to a vacuum supply, holding the wastegate closed at all times. This will be causing the car to trigger a MIL and potentially limp mode if it sees the turbo overboosting regularly. If I were you, I'd set it up like this:

Image

This layout will disable the EGR valve and air doser (increasing fuel economy, lowering smoke levels and sharpening throttle response) as well as allowing the turbocharger to build boost and function properly. You can discard all the old vacuum lines that will no longer be used, which makes things significantly easier to work with (but make sure you don't leave any leaks in the system). You'll be amazed at the difference after this, it'll feel like a new car. (NOTE: Make sure you leave all 3 EV's with their electrical connector plugged IN)

If you don't want to lose the EGR + doser system (no idea why you'd keep them, they are a hindrance and clog the intake manifold), I will do you another drawing showing how to have all 3 active, but I'd strongly recommend you follow my advice on this one.

Best Regards,
Ben.
Last edited by fattail95 on Thu Jan 12, 2017 7:09 pm, edited 1 time in total.
2001/Y Peugeot 406 2.0 HDi Saloon
150hp/330nm Powerflow stainless exhaust Kevlar clutch Cat delete EGR & Doser delete Leather interior Windows tinted Cruise control 5 dial cluster Yatour bluetooth Starfish alloys Twin rear fogs
frog
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Re: Turbo and EGR solenoid valves

Post by frog »

Nice artwork Ben! :wink:
At the moment the wastegate on your turbo is connected directly to a vacuum supply, holding the wastegate open at all times.
Indeed, the photo seems to show that the wastegate is constantly on vacuum. However, I think this will keep the wastegate closed instead of open, at all times. So then, instead, the turbo is always being spooled up to its max. At low revs that is not much. But at cruising speed and higher, there is a fairly high boost pressure. I will result in a bit lower fuel economy, and a turbo that wears faster.
NOTE: Make sure you leave all 3 EV's with their electrical connector plugged IN
My experience with an EGR solenoid plugged in electrically, but the vacuum line plugged off: the engine management computer (ECU) does not see that the EGR solenoid is not connected, so it tries to operate it. I could see this in the PP2000 while driving.

As a result, more fresh air is entering than the ECU thinks it should, since in fact the EGR is not recycling any air; all air inlet is fresh and that is measured by the mass air flow (MAF) sensor. The ECU sees this and flags a diagnostic trouble code (DTC) indicating "more air inlet than expected" or so. The DTC does not lead to any indication on the dashboard or message on the display.

When I disconnected also the electrical plugs, the ECU "knows" that the EGR solenoid is not connected and will not try to operate it. I could see this in the PP2000 while driving: EGR level went down to 0%. This will flag a different error, something like: "EGR solenoid not connected". But the measured air flow by the MAF is correct and the ECU will be able to give a smoke-free drive. And here too, the DTC does not lead to anything on the dash or display.

So my advise is to electrically disconnect the unused solenoids.
Current "fleet":
2003 406 Estate 2.0HDi 110 - 7 seater - just hit 690.000 kms :cheesy:
2001 Citroen Saxo 1.6i 8v 100

Previously owned:
2000 406 Sedan 2.0 HDi 90
2000 406 Coupé 2.0i 16v 138 - Riviera Blue

PP2000 user, can help with faults / diagnostics in the Netherlands.
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fattail95
2.0 Turbo
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Re: Turbo and EGR solenoid valves

Post by fattail95 »

frog wrote:Nice artwork Ben! :wink:
At the moment the wastegate on your turbo is connected directly to a vacuum supply, holding the wastegate open at all times.
Indeed, the photo seems to show that the wastegate is constantly on vacuum. However, I think this will keep the wastegate closed instead of open, at all times. So then, instead, the turbo is always being spooled up to its max. At low revs that is not much. But at cruising speed and higher, there is a fairly high boost pressure. I will result in a bit lower fuel economy, and a turbo that wears faster.
NOTE: Make sure you leave all 3 EV's with their electrical connector plugged IN
My experience with an EGR solenoid plugged in electrically, but the vacuum line plugged off: the engine management computer (ECU) does not see that the EGR solenoid is not connected, so it tries to operate it. I could see this in the PP2000 while driving.

As a result, more fresh air is entering than the ECU thinks it should, since in fact the EGR is not recycling any air; all air inlet is fresh and that is measured by the mass air flow (MAF) sensor. The ECU sees this and flags a diagnostic trouble code (DTC) indicating "more air inlet than expected" or so. The DTC does not lead to any indication on the dashboard or message on the display.

When I disconnected also the electrical plugs, the ECU "knows" that the EGR solenoid is not connected and will not try to operate it. I could see this in the PP2000 while driving: EGR level went down to 0%. This will flag a different error, something like: "EGR solenoid not connected". But the measured air flow by the MAF is correct and the ECU will be able to give a smoke-free drive. And here too, the DTC does not lead to anything on the dash or display.

So my advise is to electrically disconnect the unused solenoids.
Good point with respect to unplugging the solenoids, I can't imagine it makes much difference either way - the EGR system is mapped out of mine, so I've unplugged them. And very good spot, I was confusing the DW10 turbo with the DW12 turbo, no vacuum means wastegate open, and vacuum means wastegate closed as a safety measure. In this case, I'm almost certain the car will go into limp mode each time its driven, unless VERY gently. Having remapped mine, I know the turbocharger can produce 2300mbar absolute at just 1900rpm, the standard ECU file will engage limp mode if it sees a regular overboost which I'm sure it will be doing. Limp mode at the moment is the only thing preventing OPs car absolutely destroying the turbocharger, full throttle from 2000rpm onwards is enough to potentially overspeed the turbocharger if the wastegate isn't functioning. Watching PP2000 on mine, the wastegate EV duty cycle starts to decrease from 1900rpm under full throttle, and that's with the boost cap raised from 2000mbar to 2380mbar!

I did wonder if there is a vaccum leak though, as it doesn't appear as though the hole before the doser EV has been blocked? This was cause total loss of vacuum including no braking assistance, surely? If this is the case, the turbo will have no vacuum and the wastegate will be open.

Original reply edited to prevent confusion.
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Doggy
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Re: Turbo and EGR solenoid valves

Post by Doggy »

You don't normally lose servo assistance even with one of the e/v pipes disconnected as there are restrictors in the tee piece(s) off the main vacuum pump/servo pipe. These are like a solid plug with a 0.5 mm hole through it - allows the vacuum to act on the branch pipe, but ensures you don't lose the servo in the event of a pipe coming off.
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frog
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Re: Turbo and EGR solenoid valves

Post by frog »

In this case, I'm almost certain the car will go into limp mode each time its driven, unless VERY gently.
Yes, good point, I am also wondering why this setup would not lead to entering limp mode. Could very well be a vacuum leak, as you say.

I have the feeling that the turbo in the 2.0 is a bit "weaker" than the more advanced one with VNT in the 2.2 . I think that even with the wastegate permanently closed, the overboost is not so much higher than normal that it trips the ECU into limp mode. But I'm just guessing here...

See also http://www.ecuedit.com/406-2-0-hdi-rhz- ... ge10#p1563 who is talking about the 2.0 110 HDI:
Turbo usually stays between 2200 and 2300. It gets to 2300 sometimes... but it never gets to 2500 as requested :)
If I recall correctly, this turbo is rated for 1,3bar boost.
Current "fleet":
2003 406 Estate 2.0HDi 110 - 7 seater - just hit 690.000 kms :cheesy:
2001 Citroen Saxo 1.6i 8v 100

Previously owned:
2000 406 Sedan 2.0 HDi 90
2000 406 Coupé 2.0i 16v 138 - Riviera Blue

PP2000 user, can help with faults / diagnostics in the Netherlands.
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fattail95
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Re: Turbo and EGR solenoid valves

Post by fattail95 »

I feel the turbocharger referred to in that thread must have been very worn, on my car I can achieve 2400mbar with no issues at all and that still requires some wastegate intervention to keep the pressure down. I've had a few isolated incidents related to an overboost caused by a poorly fitted bung, the ECU reported "turbo pressure too high" as it was above the sensors upper limit of function (2500mbar I believe) so these turbos are capable of that with no issue.

Here is a video of a 406 HDi 110 with a stock turbo running 2430mbar boost limit

https://www.youtube.com/watch?v=_Yol87yDZmQ

It's not that our turbocharger is weaker in design than the one in the 2.2, but its fixed geometry so it is designed to function well at a certain rev range (1700rpm-3400rpm it is most efficient, with things tailing off from there in my experience). Of course it is smaller too than the 2.2 as there is less capacity to pressurise.

Ben.
2001/Y Peugeot 406 2.0 HDi Saloon
150hp/330nm Powerflow stainless exhaust Kevlar clutch Cat delete EGR & Doser delete Leather interior Windows tinted Cruise control 5 dial cluster Yatour bluetooth Starfish alloys Twin rear fogs
pugmax
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Re: Turbo and EGR solenoid valves

Post by pugmax »

fattail95 wrote:Your current EV setup is very...bodged, to say the least. At the moment the wastegate on your turbo is connected directly to a vacuum supply, holding the wastegate closed at all times. This will be causing the car to trigger a MIL and potentially limp mode if it sees the turbo overboosting regularly. If I were you, I'd set it up like this:

Image

This layout will disable the EGR valve and air doser (increasing fuel economy, lowering smoke levels and sharpening throttle response) as well as allowing the turbocharger to build boost and function properly. You can discard all the old vacuum lines that will no longer be used, which makes things significantly easier to work with (but make sure you don't leave any leaks in the system). You'll be amazed at the difference after this, it'll feel like a new car. (NOTE: Make sure you leave all 3 EV's with their electrical connector plugged IN)

If you don't want to lose the EGR + doser system (no idea why you'd keep them, they are a hindrance and clog the intake manifold), I will do you another drawing showing how to have all 3 active, but I'd strongly recommend you follow my advice on this one.

Best Regards,
Ben.
Hi Ben, Thank you for the long descriptive reply and advice. I don't want to keep EGR+doser. Could you please describe some more on connecting T-piece? The hoses which I indicated with blue arrows.

Image
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fattail95
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Re: Turbo and EGR solenoid valves

Post by fattail95 »

Hi Tila,

If you look at the brake servo, underneath the brake fluid reservoir you will see a plastic connector t-piece with a few vacuum lines coming from it. At the moment one of these lines goes straight to your turbo, and the other one will go to one of your other EV's. Block one of the two nipples off as per the diagram, and direct the other one to the input of the turbo EV (left one). Connect the output vacuum line from the EV to your turbo (already one end has been done) and ensure you have no leaks. You will have some extra pipe left over that is no longer used, keep this safe in case you ever need to return it to its original configuration.

Image

Hope that helps!

Best Regards,
Ben.
2001/Y Peugeot 406 2.0 HDi Saloon
150hp/330nm Powerflow stainless exhaust Kevlar clutch Cat delete EGR & Doser delete Leather interior Windows tinted Cruise control 5 dial cluster Yatour bluetooth Starfish alloys Twin rear fogs
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